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NI DAQMX Channel Configuration And Creation

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Greg Stoll edited this page Sep 3, 2021 · 1 revision

Channel Configuration And Creation

Create Analog Input Channels

DAQmxCreateAIAccelChan

int32 DAQmxCreateAIAccelChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], int32 terminalConfig, float64 minVal, float64 maxVal, int32 units, float64 sensitivity, int32 sensitivityUnits, int32 currentExcitSource, float64 currentExcitVal, const char customScaleName[]);

Purpose

Creates channel(s) that use an accelerometer to measure acceleration and adds the channel(s) to the task you specify with taskHandle.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
terminalConfig int32 The input terminal configuration for the channel.
Value Description
DAQmx_Val_Cfg_Default At run time, NI-DAQmx chooses the default terminal configuration for the channel.
DAQmx_Val_RSE Referenced single-ended mode
DAQmx_Val_NRSE Non-referenced single-ended mode
DAQmx_Val_Diff Differential mode
DAQmx_Val_PseudoDiff Pseudodifferential mode
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return acceleration measurements from the channel.
Name Description
DAQmx_Val_AccelUnit_g G-force (g). 1 g is approximately equal to 9.81 m/s2.
DAQmx_Val_FromCustomScale Units specified by a custom scale. Use customScaleName to specify a custom scale.
sensitivity float64 The sensitivity of the sensor. This value is in the units you specify with the sensitivityUnits input. Refer to the sensor documentation to determine this value.
sensitivityUnits int32 The units of sensitivity.
Name Description
DAQmx_Val_mVoltsPerG mVolts/g.
DAQmx_Val_VoltsPerG Volts/g.
currentExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel. You cannot use this value if the sensor requires excitation.
currentExcitVal float64 The amount of excitation, in amperes, that the sensor requires.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIAccel4WireDCVoltageChan

DAQmxCreateAIAccel4WireDCVoltageChan(TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], int32 terminalConfig, float64 minVal, float64 maxVal, int32 units, float64 sensitivity, int32 sensitivityUnits, int32 voltageExcitSource, float64 voltageExcitVal, bool32 useExcitForScaling, const char customScaleName[]);

Purpose

Creates channel(s) to measure acceleration. Use this function for custom sensors that require excitation. You can use the excitation to scale the measurement.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task used in this function.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
terminalConfig int32 The input terminal configuration for the channel.
Value Description
DAQmx_Val_Cfg_Default At run time, NI-DAQmx chooses the default terminal configuration for the channel.
DAQmx_Val_RSE Referenced single-ended mode
DAQmx_Val_NRSE Non-referenced single-ended mode
DAQmx_Val_Diff Differential mode
DAQmx_Val_PseudoDiff Pseudodifferential mode
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return from the channel.
Value Description
DAQmx_Val_FromCustomScale Units a custom scale specifies. If you select this value, you must specify a custom scale name.
DAQmx_Val_g Grams
DAQmx_Val_MetersPerSecondSquared Meters per second squared
DAQmx_Val_InchesPerSecondSquared Inches per second squared
sensitivity float64 The sensitivity of the sensor. This value is in the units you specify with the sensitivityUnits input. Refer to the sensor documentation to determine this value.
sensitivityUnits int32 The units of sensitivity.
Name Description
DAQmx_Val_mVoltsPerG Millivolts per gram
DAQmx_Val_VoltsPerG Volts per gram
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
useExcitForScaling bool32 Whether the excitation voltage will be used to scale the returned data
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIAccelChargeChan

DAQmxCreateAIAccelChargeChan(TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], int32 terminalConfig, float64 minVal, float64 maxVal, int32 units, float64 sensitivity, int32 sensitivityUnits, const char customScaleName[]);

Purpose

Creates channel(s) that use a charge-based sensor to measure acceleration.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task used in this function.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
terminalConfig int32 The input terminal configuration for the channel.
Value Description
DAQmx_Val_Cfg_Default At run time, NI-DAQmx chooses the default terminal configuration for the channel.
DAQmx_Val_RSE Referenced single-ended mode
DAQmx_Val_NRSE Non-referenced single-ended mode
DAQmx_Val_Diff Differential mode
DAQmx_Val_PseudoDiff Pseudodifferential mode
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return from the channel.
Value Description
DAQmx_Val_FromCustomScale Units a custom scale specifies. If you select this value, you must specify a custom scale name.
DAQmx_Val_AccelUnit_g Grams
DAQmx_Val_MetersPerSecondSquared Meters per second squared
DAQmx_Val_InchesPerSecondSquared Inches per second squared
sensitivity float64 The sensitivity of the sensor. This value is in the units you specify with the sensitivityUnits input. Refer to the sensor documentation to determine this value.
sensitivityUnits int32 The units of sensitivity.
Name Description
DAQmx_Val_PicoCoulombsPerG pCoulomb/g
DAQmx_Val_PicoCoulombsPerMetersPerSecondSquared pCoulomb/(m/s^2)
DAQmx_Val_PicoCoulombsPerInchesPerSecondSquared pCoulomb/(in/s^2)
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIBridgeChan

int32 DAQmxCreateAIBridgeChan(TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 bridgeConfig, int32 voltageExcitSource, float64 voltageExcitVal, float64 nominalBridgeResistance, const char customScaleName[]);

Purpose

Creates channel(s) that measure voltage ratios from a Wheatstone bridge.

Use this instance with bridge-based sensors that measure phenomena other than strain, force, pressure, or torque, or that scale data to physical units NI-DAQmx does not support.

Use a custom scale or other scaling code to convert the voltage ratios to physical units.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 Specifies in which unit to return voltage ratios from the channel.
Name Description
DAQmx_Val_VoltsPerVolt volts per volt
DAQmx_Val_mVoltsPerVolt millivolts per volt
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
bridgeConfig int32 Specifies the Wheatstone bridge configuration connected to the channel.
Value Description
DAQmx_Val_FullBridge Four active sensing elements in the bridge
DAQmx_Val_HalfBridge Two active sensing elements in the bridge
DAQmx_Val_QuarterBridge One active sensing element in the bridge
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
nominalBridgeResistance float64 Specifies in ohms the resistance of the bridge while not under load.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIChargeChan

DAQmxCreateAIChargeChan(TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], int32 terminalConfig, float64 minVal, float64 maxVal, int32 units, const char customScaleName[]);

Purpose

Creates channel(s) that use a sensor with charge output.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task used in this function.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
terminalConfig int32 The input terminal configuration for the channel.
Value Description
DAQmx_Val_Cfg_Default At run time, NI-DAQmx chooses the default terminal configuration for the channel.
DAQmx_Val_RSE Referenced single-ended mode
DAQmx_Val_NRSE Non-referenced single-ended mode
DAQmx_Val_Diff Differential mode
DAQmx_Val_PseudoDiff Pseudodifferential mode
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return from the channel.
Value Description
DAQmx_Val_FromCustomScale Units a custom scale specifies. If you select this value, you must specify a custom scale name.
DAQmx_Val_Coulombs Coulombs
DAQmx_Val_PicoCoulombs Picocoulombs
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAICurrentChan

int32 DAQmxCreateAICurrentChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], int32 terminalConfig, float64 minVal, float64 maxVal, int32 units, int32 shuntResistorLoc, float64 extShuntResistorVal, const char customScaleName[]);

Purpose

Creates channel(s) for current measurement and adds the channel(s) to the task you specify with taskHandle.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
terminalConfig int32 The input terminal configuration for the channel.
Value Description
DAQmx_Val_Cfg_Default At run time, NI-DAQmx chooses the default terminal configuration for the channel.
DAQmx_Val_RSE Referenced single-ended mode
DAQmx_Val_NRSE Non-referenced single-ended mode
DAQmx_Val_Diff Differential mode
DAQmx_Val_PseudoDiff Pseudodifferential mode
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the measurement.
Value Description
DAQmx_Val_Amps amperes
DAQmx_Val_FromCustomScale Units a custom scale specifies. If you select this value, you must specify a custom scale name.
shuntResistorLoc int32 The location of the shunt resistor.
Value Description
DAQmx_Val_Default At run time, NI-DAQmx chooses the default shunt resistor location for the channel.
DAQmx_Val_Internal Use the built-in shunt resistor of the device.
DAQmx_Val_External Use a shunt resistor external to the device. You must specify the value of the shunt resistor in extShuntResistorVal.
extShuntResistorVal float64 The value, in ohms, of an external shunt resistor.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAICurrentRMSChan

int32 DAQmxCreateAICurrentRMSChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], int32 terminalConfig, float64 minVal, float64 maxVal, int32 units, int32 shuntResistorLoc, float64 extShuntResistorVal, const char customScaleName[]);

Purpose

Creates channel(s) for RMS current measurement and adds the channel(s) to the task you specify with taskHandle.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
terminalConfig int32 The input terminal configuration for the channel.
Value Description
DAQmx_Val_Cfg_Default At run time, NI-DAQmx chooses the default terminal configuration for the channel.
DAQmx_Val_RSE Referenced single-ended mode
DAQmx_Val_NRSE Non-referenced single-ended mode
DAQmx_Val_Diff Differential mode
DAQmx_Val_PseudoDiff Pseudodifferential mode
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the measurement.
Value Description
DAQmx_Val_Amps amperes
DAQmx_Val_FromCustomScale Units a custom scale specifies. If you select this value, you must specify a custom scale name.
shuntResistorLoc int32 The location of the shunt resistor.
Value Description
DAQmx_Val_Default At run time, NI-DAQmx chooses the default shunt resistor location for the channel.
DAQmx_Val_Internal Use the built-in shunt resistor of the device.
DAQmx_Val_External Use a shunt resistor external to the device. You must specify the value of the shunt resistor in extShuntResistorVal.
extShuntResistorVal float64 The value, in ohms, of an external shunt resistor.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIForceBridgePolynomialChan

int32 DAQmxCreateAIForceBridgePolynomialChan(TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 bridgeConfig, int32 voltageExcitSource, float64 voltageExcitVal, float64 nominalBridgeResistance, const float64 forwardCoeffs[], uInt32 numForwardCoeffs, const float64 reverseCoeffs[], uInt32 numReverseCoeffs, int32 electricalUnits, int32 physicalUnits, const char customScaleName[]);

Purpose

Creates channel(s) that use a Wheatstone bridge to measure force or load.

Use this instance with sensors whose specifications provide a polynomial to convert electrical values to physical values.

When you use this scaling type, NI-DAQmx requires coefficients for a polynomial that converts electrical values to physical values (forward), as well as coefficients for a polynomial that converts physical values to electrical values (reverse). If you only know one set of coefficients, use the DAQmxCalculateReversePolyCoeff function to generate the other set.

Specify different values for units and physicalUnits if the sensor specifications provide physical values in one unit, but you want NI-DAQmx to scale data to a different unit.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 Specifies in which unit to return force measurements from the channel.
Name Description
DAQmx_Val_Newtons newtons
DAQmx_Val_Pounds pounds
DAQmx_Val_KilogramForce kilograms-force
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
bridgeConfig int32 Specifies the Wheatstone bridge configuration connected to the channel.
Value Description
DAQmx_Val_FullBridge Four active sensing elements in the bridge
DAQmx_Val_HalfBridge Two active sensing elements in the bridge
DAQmx_Val_QuarterBridge One active sensing element in the bridge
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
nominalBridgeResistance float64 Specifies in ohms the resistance of the bridge while not under load.
forwardCoeffs const float64 [] An array of coefficients for the polynomial that converts electrical values to physical values. Each element of the array corresponds to a term of the equation. For example, if index three of the array is 9, the fourth term of the equation is 9x^3.
numForwardCoeffs uInt32 The number of coefficients in the forwardCoeffs array.
reverseCoeffs const float64 [] An array of coefficients for the polynomial that converts physical values to electrical values. Each element of the array corresponds to a term of the equation. For example, if index three of the array is 9, the fourth term of the equation is 9x^3.
numReverseCoeffs uInt32 The number of coefficients in the reverseCoeffs array.
electricalUnits int32 Specifies from which electrical unit to scale data. Select the same unit that the sensor data sheet or calibration certificate uses for electrical values.
Value Description
DAQmx_Val_VoltsPerVolt volts per volt
DAQmx_Val_mVoltsPerVolt millivolts per volt
physicalUnits int32 Specifies to which physical units to scale electrical data. Select the same unit that the sensor data sheet or calibration certificate uses for physical values.
Value Description
DAQmx_Val_Newtons newtons
DAQmx_Val_Pounds pounds
DAQmx_Val_KilogramForce kilograms-force
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIForceBridgeTableChan

int32 DAQmxCreateAIForceBridgeTableChan(TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 bridgeConfig, int32 voltageExcitSource, float64 voltageExcitVal, float64 nominalBridgeResistance, const float64 electricalVals[], uInt32 numElectricalVals, int32 electricalUnits, const float64 physicalVals[], uInt32 numPhysicalVals, int32 physicalUnits, const char customScaleName[]);

Purpose

Creates channel(s) that use a Wheatstone bridge to measure force or load.

Use this instance with sensors whose specifications provide a table of electrical values and the corresponding physical values.

When you use this scaling type, NI-DAQmx performs linear scaling between each pair of electrical and physical values. The input limits specified with minVal and maxVal must fall within the smallest and largest physical values. For any data outside those endpoints, NI-DAQmx coerces that data to the endpoints.

Specify different values for units and physicalUnits if the sensor specifications provide physical values in one unit, but you want NI-DAQmx to scale data to a different unit.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 Specifies in which unit to return force measurements from the channel.
Name Description
DAQmx_Val_Newtons newtons
DAQmx_Val_Pounds pounds
DAQmx_Val_KilogramForce kilograms-force
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
bridgeConfig int32 Specifies the Wheatstone bridge configuration connected to the channel.
Value Description
DAQmx_Val_FullBridge Four active sensing elements in the bridge
DAQmx_Val_HalfBridge Two active sensing elements in the bridge
DAQmx_Val_QuarterBridge One active sensing element in the bridge
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
nominalBridgeResistance float64 Specifies in ohms the resistance of the bridge while not under load.
electricalVals const float64 [] The array of electrical values that map to the values in physicalVals. Specify this value in the unit indicated by electricalUnits.
numElectricalVals uInt32 The number of electrical values in the electricalVals array.
electricalUnits int32 Specifies from which electrical unit to scale data. Select the same unit that the sensor data sheet or calibration certificate uses for electrical values.
Value Description
DAQmx_Val_VoltsPerVolt volts per volt
DAQmx_Val_mVoltsPerVolt millivolts per volt
physicalVals const float64 [] The array of physical values that map to the values in electricalVals. Specify this value in the unit indicated by physicalUnits.
numPhysicalVals uInt32 The number of physical values in the physicalVals array.
physicalUnits int32 Specifies to which physical units to scale electrical data. Select the same unit that the sensor data sheet or calibration certificate uses for physical values.
Value Description
DAQmx_Val_Newtons newtons
DAQmx_Val_Pounds pounds
DAQmx_Val_KilogramForce kilograms-force
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIForceBridgeTwoPointLinChan

int32 DAQmxCreateAIForceBridgeTwoPointLinChan(TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 bridgeConfig, int32 voltageExcitSource, float64 voltageExcitVal, float64 nominalBridgeResistance, float64 firstElectricalVal, float64 secondElectricalVal, int32 electricalUnits, float64 firstPhysicalVal, float64 secondPhysicalVal, int32 physicalUnits, const char customScaleName[]);

Purpose

Creates channel(s) that use a Wheatstone bridge to measure force or load.

Use this instance with sensors whose specifications do not provide a polynomial for scaling or a table of electrical and physical values.

When you use this scaling type, NI-DAQmx uses two points of electrical and physical values to calculate the slope and y-intercept of a linear equation and uses that equation to scale electrical values to physical values.

Specify different values for units and physicalUnits if the sensor specifications provide physical values in one unit, but you want NI-DAQmx to scale data to a different unit.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 Specifies in which unit to return force measurements from the channel.
Name Description
DAQmx_Val_Newtons newtons
DAQmx_Val_Pounds pounds
DAQmx_Val_KilogramForce kilograms-force
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
bridgeConfig int32 Specifies the Wheatstone bridge configuration connected to the channel.
Value Description
DAQmx_Val_FullBridge Four active sensing elements in the bridge
DAQmx_Val_HalfBridge Two active sensing elements in the bridge
DAQmx_Val_QuarterBridge One active sensing element in the bridge
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
nominalBridgeResistance float64 Specifies in ohms the resistance of the bridge while not under load.
firstElectricalVal float64 The first electrical value, corresponding to firstPhysicalVal. Specify this value in the unit indicated by electricalUnits.
secondElectricalVal float64 The second electrical value, corresponding to secondPhysicalVal. Specify this value in the unit indicated by electricalUnits.
electricalUnits int32 Specifies from which electrical unit to scale data. Select the same unit that the sensor data sheet or calibration certificate uses for electrical values.
Value Description
DAQmx_Val_VoltsPerVolt volts per volt
DAQmx_Val_mVoltsPerVolt millivolts per volt
firstPhysicalVal float64 The first physical value, corresponding to firstElectricalVal. Specify this value in the unit indicated by physicalUnits.
secondPhysicalVal float64 The second physical value, corresponding to secondElectricalValue. Specify this value in the unit indicated by physicalUnits.
physicalUnits int32 Specifies to which physical units to scale electrical data. Select the same unit that the sensor data sheet or calibration certificate uses for physical values.
Value Description
DAQmx_Val_Newtons newtons
DAQmx_Val_Pounds pounds
DAQmx_Val_KilogramForce kilograms-force
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIForceIEPEChan

int32 DAQmxCreateAIForceIEPEChan(TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], int32 terminalConfig, float64 minVal, float64 maxVal, int32 units, float64 sensitivity, int32 sensitivityUnits, int32 currentExcitSource, float64 currentExcitVal, const char customScaleName[]);

Purpose

Creates channel(s) that use an IEPE force sensor to measure force or load.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
terminalConfig int32 The input terminal configuration for the channel.
Value Description
DAQmx_Val_Cfg_Default At run time, NI-DAQmx chooses the default terminal configuration for the channel.
DAQmx_Val_RSE Referenced single-ended mode
DAQmx_Val_NRSE Non-referenced single-ended mode
DAQmx_Val_Diff Differential mode
DAQmx_Val_PseudoDiff Pseudodifferential mode
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 Specifies in which unit to return force measurements from the channel.
Name Description
DAQmx_Val_Newtons newtons
DAQmx_Val_Pounds pounds
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
sensitivity float64 The sensitivity of the sensor. This value is in the units you specify with the sensitivityUnits input. Refer to the sensor documentation to determine this value.
sensitivityUnits int32 The units of sensitivity input.
Name Description
DAQmx_Val_mVoltsPerNewton millivolts per newton
DAQmx_Val_mVoltsPerPound millivolts per pound
currentExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel. You cannot use this value if the sensor requires excitation.
currentExcitVal float64 The amount of excitation, in amperes, that the sensor requires.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIFreqVoltageChan

int32 DAQmxCreateAIFreqVoltageChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, float64 thresholdLevel, float64 hysteresis, const char customScaleName[]);

Purpose

Creates channel(s) that use a frequency-to-voltage converter to measure frequency and adds the channel(s) to the task you specify with taskHandle.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the measurement.
Name Description
DAQmx_Val_Hz hertz
DAQmx_Val_FromCustomScale Units specified by a custom scale. Use customScaleName to specify a custom scale.
thresholdLevel float64 The voltage level at which to recognize waveform repetitions.
hysteresis float64 Specifies in volts a window below thresholdLevel. The input voltage must pass below thresholdLevel minus hysteresis before NI-DAQmx recognizes a waveform repetition. Hysteresis can improve measurement accuracy when the signal contains noise or jitter.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIMicrophoneChan

int32 DAQmxCreateAIMicrophoneChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], int32 terminalConfig, int32 units, float64 micSensitivity, float64 maxSndPressLevel, int32 currentExcitSource, float64 currentExcitVal, const char customScaleName[]);

Purpose

Creates channel(s) that use a microphone to measure sound pressure and adds the channel(s) to the task you specify with taskHandle.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task used in this function.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
terminalConfig int32 The input terminal configuration for the channel.
Value Description
DAQmx_Val_Cfg_Default At run time, NI-DAQmx chooses the default terminal configuration for the channel.
DAQmx_Val_RSE Referenced single-ended mode
DAQmx_Val_NRSE Non-referenced single-ended mode
DAQmx_Val_Diff Differential mode
DAQmx_Val_PseudoDiff Pseudodifferential mode
units int32 The units to use to return sound pressure measurements.
Name Description
DAQmx_Val_Pascals pascals
DAQmx_Val_FromCustomScale Units specified by a custom scale. Use customScaleName to specify a custom scale.
micSensitivity float64 The sensitivity of the microphone. Specify this value in millivolts per pascal.
maxSndPressLevel float64 The maximum instantaneous sound pressure level you expect to measure. This value is in decibels, referenced to 20 micropascals.
currentExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel. You cannot use this value if the sensor requires excitation.
currentExcitVal float64 The amount of excitation, in amperes, that the sensor requires.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIPressureBridgePolynomialChan

int32 DAQmxCreateAIPressureBridgePolynomialChan(TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 bridgeConfig, int32 voltageExcitSource, float64 voltageExcitVal, float64 nominalBridgeResistance, const float64 forwardCoeffs[], uInt32 numForwardCoeffs, const float64 reverseCoeffs[], uInt32 numReverseCoeffs, int32 electricalUnits, int32 physicalUnits, const char customScaleName[]);

Purpose

Creates channel(s) that use a Wheatstone bridge to measure pressure.

Use this instance with sensors whose specifications provide a polynomial to convert electrical values to physical values.

When you use this scaling type, NI-DAQmx requires coefficients for a polynomial that converts electrical values to physical values (forward), as well as coefficients for a polynomial that converts physical values to electrical values (reverse). If you only know one set of coefficients, use the DAQmxCalculateReversePolyCoeff function to generate the other set.

Specify different values for units and physicalUnits if the sensor specifications provide physical values in one unit, but you want NI-DAQmx to scale data to a different unit.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 Specifies in which unit to return pressure measurements from the channel.
Name Description
DAQmx_Val_PoundsPerSquareInch pounds per square inch
DAQmx_Val_Bar bar
DAQmx_Val_Pascals pascals
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
bridgeConfig int32 Specifies the Wheatstone bridge configuration connected to the channel.
Value Description
DAQmx_Val_FullBridge Four active sensing elements in the bridge
DAQmx_Val_HalfBridge Two active sensing elements in the bridge
DAQmx_Val_QuarterBridge One active sensing element in the bridge
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
nominalBridgeResistance float64 Specifies in ohms the resistance of the bridge while not under load.
forwardCoeffs const float64 [] An array of coefficients for the polynomial that converts electrical values to physical values. Each element of the array corresponds to a term of the equation. For example, if index three of the array is 9, the fourth term of the equation is 9x^3.
numForwardCoeffs uInt32 The number of coefficients in the forwardCoeffs array.
reverseCoeffs const float64 [] An array of coefficients for the polynomial that converts physical values to electrical values. Each element of the array corresponds to a term of the equation. For example, if index three of the array is 9, the fourth term of the equation is 9x^3.
numReverseCoeffs uInt32 The number of coefficients in the reverseCoeffs array.
electricalUnits int32 Specifies from which electrical unit to scale data. Select the same unit that the sensor data sheet or calibration certificate uses for electrical values.
Value Description
DAQmx_Val_VoltsPerVolt volts per volt
DAQmx_Val_mVoltsPerVolt millivolts per volt
physicalUnits int32 Specifies to which physical unit to scale electrical data. Select the same unit that the sensor data sheet or calibration certificate uses for physical values.
Value Description
DAQmx_Val_PoundsPerSquareInch pounds per square inch
DAQmx_Val_Bar bar
DAQmx_Val_Pascals pascals
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIPressureBridgeTableChan

int32 DAQmxCreateAIPressureBridgeTableChan(TaskHandle taskHandle,const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal,float64 maxVal, int32 units, int32 bridgeConfig, int32 voltageExcitSource, float64 voltageExcitVal, float64 nominalBridgeResistance, const float64 electricalVals[], uInt32 numElectricalVals, int32 electricalUnits, const float64 physicalVals[], uInt32 numPhysicalVals, int32 physicalUnits, const char customScaleName[]);

Purpose

Creates channel(s) that use a Wheatstone bridge to measure pressure.

Use this instance with sensors whose specifications provide a table of electrical values and the corresponding physical values.

When you use this scaling type, NI-DAQmx performs linear scaling between each pair of electrical and physical values. The input limits specified with minVal and maxVal must fall within the smallest and largest physical values. For any data outside those endpoints, NI-DAQmx coerces that data to the endpoints.

Specify different values for units and physicalUnits if the sensor specifications provide physical values in one unit, but you want NI-DAQmx to scale data to a different unit.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 Specifies in which unit to return pressure measurements from the channel.
Name Description
DAQmx_Val_PoundsPerSquareInch pounds per square inch
DAQmx_Val_Bar bar
DAQmx_Val_Pascals pascals
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
bridgeConfig int32 Specifies the Wheatstone bridge configuration connected to the channel.
Value Description
DAQmx_Val_FullBridge Four active sensing elements in the bridge
DAQmx_Val_HalfBridge Two active sensing elements in the bridge
DAQmx_Val_QuarterBridge One active sensing element in the bridge
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
nominalBridgeResistance float64 Specifies in ohms the resistance of the bridge while not under load.
electricalVals const float64 [] The array of electrical values that map to the values in physicalVals. Specify this value in the unit indicated by electricalUnits.
numElectricalVals uInt32 The number of electrical values in the electricalVals array.
electricalUnits int32 Specifies from which electrical unit to scale data. Select the same unit that the sensor data sheet or calibration certificate uses for electrical values.
Value Description
DAQmx_Val_VoltsPerVolt volts per volt
DAQmx_Val_mVoltsPerVolt millivolts per volt
physicalVals const float64 [] The array of physical values that map to the values in electricalVals. Specify this value in the unit indicated by physicalUnits.
numPhysicalVals uInt32 The number of physical values in the physicalVals array.
physicalUnits int32 Specifies to which physical unit to scale electrical data. Select the same unit that the sensor data sheet or calibration certificate uses for physical values.
Value Description
DAQmx_Val_PoundsPerSquareInch pounds per square inch
DAQmx_Val_Bar bar
DAQmx_Val_Pascals pascals
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIPressureBridgeTwoPointLinChan

int32 DAQmxCreateAIPressureBridgeTwoPointLinChan(TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 bridgeConfig, int32 voltageExcitSource, float64 voltageExcitVal, float64 nominalBridgeResistance, float64 firstElectricalVal, float64 secondElectricalVal, int32 electricalUnits, float64 firstPhysicalVal, float64 secondPhysicalVal, int32 physicalUnits, const char customScaleName[]);

Purpose

Creates channel(s) that use a Wheatstone bridge to measure pressure.

Use this instance with sensors whose specifications do not provide a polynomial for scaling or a table of electrical and physical values.

When you use this scaling type, NI-DAQmx uses two points of electrical and physical values to calculate the slope and y-intercept of a linear equation and uses that equation to scale electrical values to physical values.

Specify different values for units and physicalUnits if the sensor specifications provide physical values in one unit, but you want NI-DAQmx to scale data to a different unit.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 Specifies in which unit to return pressure measurements from the channel.
Name Description
DAQmx_Val_PoundsPerSquareInch pounds per square inch
DAQmx_Val_Bar bar
DAQmx_Val_Pascals pascals
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
bridgeConfig int32 Specifies the Wheatstone bridge configuration connected to the channel.
Value Description
DAQmx_Val_FullBridge Four active sensing elements in the bridge
DAQmx_Val_HalfBridge Two active sensing elements in the bridge
DAQmx_Val_QuarterBridge One active sensing element in the bridge
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
nominalBridgeResistance float64 Specifies in ohms the resistance of the bridge while not under load.
firstElectricalVal float64 The first electrical value, corresponding to firstPhysicalVal. Specify this value in the unit indicated by electricalUnits.
secondElectricalVal float64 The second electrical value, corresponding to secondPhysicalVal. Specify this value in the unit indicated by electricalUnits.
electricalUnits int32 Specifies from which electrical unit to scale data. Select the same unit that the sensor data sheet or calibration certificate uses for electrical values.
Value Description
DAQmx_Val_VoltsPerVolt volts per volt
DAQmx_Val_mVoltsPerVolt millivolts per volt
firstPhysicalVal float64 The first physical value, corresponding to firstElectricalVal. Specify this value in the unit indicated by physicalUnits.
secondPhysicalVal float64 The second physical value, corresponding to secondElectricalValue. Specify this value in the unit indicated by physicalUnits.
physicalUnits int32 Specifies to which physical unit to scale electrical data. Select the same unit that the sensor data sheet or calibration certificate uses for physical values.
Value Description
DAQmx_Val_PoundsPerSquareInch pounds per square inch
DAQmx_Val_Bar bar
DAQmx_Val_Pascals pascals
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIResistanceChan

int32 DAQmxCreateAIResistanceChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 resistanceConfig, int32 currentExcitSource, float64 currentExcitVal, const char customScaleName[]);

Purpose

Create channel(s) to measure resistance and adds the channel(s) to the task you specify with taskHandle.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the measurement.
Name Description
DAQmx_Val_Ohms ohms
DAQmx_Val_FromCustomScale Units specified by a custom scale. Use customScaleName to specify a custom scale.
resistanceConfig int32 The configuration for resistance measurements.
Value Description
DAQmx_Val_2Wire 2-wire mode.
DAQmx_Val_3Wire 3-wire mode.
DAQmx_Val_4Wire 4-wire mode.
currentExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel. You cannot use this value if the sensor requires excitation.
currentExcitVal float64 The amount of excitation, in amperes, that the sensor requires.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIRosetteStrainGageChan

int32 DAQmxCreateAIRosetteStrainGageChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 rosetteType, float64 gageOrientation, const int32 rosetteMeasTypes[], uInt32 numRosetteMeasTypes, int32 strainConfig, int32 voltageExcitSource, float64 voltageExcitVal, float64 gageFactor, float64 nominalGageResistance, float64 poissonRatio, float64 leadWireResistance);

Purpose

Creates channel(s) to measure strain and adds the channel(s) to the task you specify with taskHandle.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 Specifies the minimum strain you expect to measure. This value applies to each strain gage in the rosette.
maxVal float64 Specifies the maximum strain you expect to measure. This value applies to each strain gage in the rosette.
rosetteType int32 Specifies the type of the rosette.
Value Description
DAQmx_Val_RectangularRosette A rectangular rosette consists of three strain gages, each separated by a 45 degree angle.
DAQmx_Val_DeltaRosette A delta rosette consists of three strain gages, each separated by a 60 degree angle.
DAQmx_Val_TeeRosette A tee rosette consists of two strain gages oriented at 90 degrees with respect to each other.
gageOrientation float64 Specifies, in degrees, the orientation of the gage with respect to the preferred X axis. This parameter applies only to Cartesian measurements.
rosetteMeasTypes const int32 [] Specifies the virtual channels to create for the rosette measurements. For each rosette sensor, the function creates one strain virtual channel for each strain gage in the rosette, and one rosette virtual channel for each measurement specified in the rosette measurements array.
Value Description
DAQmx_Val_PrincipalStrain1 The maximum tensile strain coplanar to the surface of the material under stress.
DAQmx_Val_PrincipalStrain2 The minimum tensile strain coplanar to the surface of the material under stress.
DAQmx_Val_PrincipalStrainAngle The angle, in degrees, at which the principal strains of the rosette occur with respect to the preferred X axis. The range is -180 degrees to 180 degrees, where negative values are angles below the X axis. For tee rosettes, this value is 0 degrees.
DAQmx_Val_CartesianStrainX The tensile strain coplanar to the surface of the material under stress in the X coordinate direction.
DAQmx_Val_CartesianStrainY The tensile strain coplanar to the surface of the material under stress in the Y coordinate direction.
DAQmx_Val_CartesianShearStrainXY The strain coplanar to the cross section of the material under stress in the XY coordinate direction.
DAQmx_Val_MaxShearStrain The maximum strain coplanar to the cross section of the material under stress.
DAQmx_Val_MaxShearStrainAngle The angle, in degrees, at which the maximum shear strain of the rosette occurs with respect to the preferred X axis. The range is -125 degrees to 225 degrees, where negative values are angles below the X axis. Maximum shear strain angle occurs at an offset of 45 degrees relative to the principal strain angle. For tee rosettes, this value is 45 degrees.
numRosetteMeasTypes uInt32 Specifies the number of virtual channels used in rosetteMeasTypes.
strainConfig int32 The strain gage bridge configuration.
Note Typical rosette sensors use the DAQmx_Val_QuarterBridgeI strain configuration.
Value Description
DAQmx_Val_FullBridgeI Four active gages with two pairs subjected to equal and opposite strains.
DAQmx_Val_FullBridgeII Four active gages with two aligned with maximum principal strain and two Poisson gages in adjacent arms.
DAQmx_Val_FullBridgeIII Four active gages with two aligned with maximum principal strain and two Poisson gages in opposite arms.
DAQmx_Val_HalfBridgeI Two active gages with one aligned with maximum principal strain and one Poisson gage.
DAQmx_Val_HalfBridgeII Two active gages with equal and opposite strains.
DAQmx_Val_QuarterBridgeI Single active gage.
DAQmx_Val_QuarterBridgeII Single active gage and one dummy gage.
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
gageFactor float64 The sensitivity of the strain gages and relates the change in electrical resistance to the change in strain. Each gage in the bridge must have the same gage factor. Refer to the sensor documentation to determine this value.
nominalGageResistance float64 The resistance, in ohms, of the gages in an unstrained position. Each gage in the bridge must have the same nominal gage resistance. The resistance across arms of the bridge that do not have strain gages must also be the same as the nominal gage resistance. Refer to the sensor documentation to determine this value.
poissonRatio float64 The ratio of lateral strain to axial strain in the material in which you measure strain.
leadWireResistance float64 The amount, in ohms, of resistance in the lead wires. Ideally, this value is the same for all leads.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIRTDChan

int32 DAQmxCreateAIRTDChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 rtdType, int32 resistanceConfig, int32 currentExcitSource, float64 currentExcitVal, float64 r0);

Purpose

Creates channel(s) that use an RTD to measure temperature and adds the channel(s) to the task you specify with taskHandle.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the measurement.
Name Description
DAQmx_Val_DegC degrees Celsius
DAQmx_Val_DegF degrees Fahrenheit
DAQmx_Val_Kelvins kelvins
DAQmx_Val_DegR degrees Rankine
rtdType int32 The type of RTD connected to the channel.
Value Description
DAQmx_Val_Pt3750 Pt3750
DAQmx_Val_Pt3851 Pt3851
DAQmx_Val_Pt3911 Pt3911
DAQmx_Val_Pt3916 Pt3916
DAQmx_Val_Pt3920 Pt3920
DAQmx_Val_Pt3928 Pt3928
DAQmx_Val_Custom You must specify the 'A', 'B', and 'C' constants for the Callendar-Van Dusen equation
resistanceConfig int32 The configuration for resistance measurements.
Value Description
DAQmx_Val_2Wire 2-wire mode.
DAQmx_Val_3Wire 3-wire mode.
DAQmx_Val_4Wire 4-wire mode.
currentExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel. You cannot use this value if the sensor requires excitation.
currentExcitVal float64 The amount of excitation, in amperes, that the sensor requires.
r0 float64 The sensor resistance in ohms at 0 deg C for the Callendar-Van Dusen equation Refer to the sensor documentation to determine this value.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIStrainGageChan

int32 DAQmxCreateAIStrainGageChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 strainConfig, int32 voltageExcitSource, float64 voltageExcitVal, float64 gageFactor, float64 initialBridgeVoltage, float64 nominalGageResistance, float64 poissonRatio, float64 leadWireResistance, const char customScaleName[]);

Purpose

Creates channel(s) to measure strain and adds the channel(s) to the task you specify with taskHandle.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the measurement.
Name Description
DAQmx_Val_Strain Strain
DAQmx_Val_FromCustomScale Units specified by a custom scale. Use customScaleName to specify a custom scale.
strainConfig int32 The strain gage bridge configuration.
Value Description
DAQmx_Val_FullBridgeI Four active gages with two pairs subjected to equal and opposite strains.
DAQmx_Val_FullBridgeII Four active gages with two aligned with maximum principal strain and two Poisson gages in adjacent arms.
DAQmx_Val_FullBridgeIII Four active gages with two aligned with maximum principal strain and two Poisson gages in opposite arms.
DAQmx_Val_HalfBridgeI Two active gages with one aligned with maximum principal strain and one Poisson gage.
DAQmx_Val_HalfBridgeII Two active gages with equal and opposite strains.
DAQmx_Val_QuarterBridgeI Single active gage.
DAQmx_Val_QuarterBridgeII Single active gage and one dummy gage.
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
gageFactor float64 The sensitivity of the strain gages and relates the change in electrical resistance to the change in strain. Each gage in the bridge must have the same gage factor. Refer to the sensor documentation to determine this value.
initialBridgeVoltage float64 The bridge output voltage in the unloaded condition. NI-DAQmx subtracts this value from any measurements before applying scaling equations. Perform a voltage measurement on the bridge with no strain applied to determine this value.
nominalGageResistance float64 The resistance, in ohms, of the gages in an unstrained position. Each gage in the bridge must have the same nominal gage resistance. The resistance across arms of the bridge that do not have strain gages must also be the same as the nominal gage resistance. Refer to the sensor documentation to determine this value.
poissonRatio float64 The ratio of lateral strain to axial strain in the material in which you measure strain.
leadWireResistance float64 The amount, in ohms, of resistance in the lead wires. Ideally, this value is the same for all leads.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAITempBuiltInSensorChan

int32 DAQmxCreateAITempBuiltInSensorChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], int32 units);

Purpose

Creates channel(s) to measure temperature with a built-in sensor of a terminal block or device and adds the channel(s) to the task you specify with taskHandle. On SCXI modules, for example, this could be the CJC sensor.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
units int32 The units to use to return the measurement.
Name Description
DAQmx_Val_DegC degrees Celsius
DAQmx_Val_DegF degrees Fahrenheit
DAQmx_Val_Kelvins kelvins
DAQmx_Val_DegR degrees Rankine

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIThrmcplChan

int32 DAQmxCreateAIThrmcplChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 thermocoupleType, int32 cjcSource, float64 cjcVal, const char cjcChannel[]);

Purpose

Creates channel(s) that use a thermocouple to measure temperature and adds the channel(s) to the task you specify with taskHandle.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the measurement.
Name Description
DAQmx_Val_DegC degrees Celsius
DAQmx_Val_DegF degrees Fahrenheit
DAQmx_Val_Kelvins kelvins
DAQmx_Val_DegR degrees Rankine
thermocoupleType int32 The type of thermocouple connected to the channel.
Value Description
DAQmx_Val_J_Type_TC J-type thermocouple.
DAQmx_Val_K_Type_TC K-type thermocouple.
DAQmx_Val_N_Type_TC N-type thermocouple.
DAQmx_Val_R_Type_TC R-type thermocouple.
DAQmx_Val_S_Type_TC S-type thermocouple.
DAQmx_Val_T_Type_TC T-type thermocouple.
DAQmx_Val_B_Type_TC B-type thermocouple.
DAQmx_Val_E_Type_TC E-type thermocouple.
cjcSource int32 The source of cold junction compensation.
Value Description
DAQmx_Val_BuiltIn Use a cold-junction compensation channel built into the terminal block.
DAQmx_Val_ConstVal You must specify the cold-junction temperature.
DAQmx_Val_Chan Use a channel for cold-junction compensation.
cjcVal float64 The temperature of the cold junction of the thermocouple if you set cjcSource to DAQmx_Val_ConstVal.
cjcChannel const char [] The channel that acquires the temperature of the thermocouple cold-junction if you set cjcSource to DAQmx_Val_Chan. You can use a global channel or another virtual channel already in the task. If the channel is a temperature channel, NI-DAQmx acquires the temperature in the correct units. Other channel types, such as a resistance channel with a custom sensor, must use a custom scale to scale values to degrees Celsius.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIThrmstrChanIex

int32 DAQmxCreateAIThrmstrChanIex (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 resistanceConfig, int32 currentExcitSource, float64 currentExcitVal, float64 a, float64 b, float64 c);

Purpose

Creates channel(s) that use a thermistor to measure temperature and adds the channel(s) to the task you specify with taskHandle. Use this function when the thermistor requires current excitation.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the measurement.
Name Description
DAQmx_Val_DegC degrees Celsius
DAQmx_Val_DegF degrees Fahrenheit
DAQmx_Val_Kelvins kelvins
DAQmx_Val_DegR degrees Rankine
resistanceConfig int32 The configuration for resistance measurements.
Value Description
DAQmx_Val_2Wire 2-wire mode.
DAQmx_Val_3Wire 3-wire mode.
DAQmx_Val_4Wire 4-wire mode.
currentExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel. You cannot use this value if the sensor requires excitation.
currentExcitVal float64 The amount of excitation, in amperes, that the sensor requires.
a float64 The A constant from the Steinhart-Hart thermistor equation.
b float64 The B constant from the Steinhart-Hart thermistor equation.
c float64 The C constant from the Steinhart-Hart thermistor equation.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIThrmstrChanVex

int32 DAQmxCreateAIThrmstrChanVex (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 resistanceConfig, int32 voltageExcitSource, float64 voltageExcitVal, float64 a, float64 b, float64 c, float64 r1);

Purpose

Creates channel(s) that use a thermistor to measure temperature and adds the channel(s) to the task you specify with taskHandle. Use this function when the thermistor requires voltage excitation.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the measurement.
Name Description
DAQmx_Val_DegC degrees Celsius
DAQmx_Val_DegF degrees Fahrenheit
DAQmx_Val_Kelvins kelvins
DAQmx_Val_DegR degrees Rankine
resistanceConfig int32 The configuration for resistance measurements.
Value Description
DAQmx_Val_2Wire 2-wire mode.
DAQmx_Val_3Wire 3-wire mode.
DAQmx_Val_4Wire 4-wire mode.
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
a float64 The A constant from the Steinhart-Hart thermistor equation.
b float64 The B constant from the Steinhart-Hart thermistor equation.
c float64 The C constant from the Steinhart-Hart thermistor equation.
r1 float64 The value, in ohms, of the reference resistor.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAITorqueBridgePolynomialChan

int32 DAQmxCreateAITorqueBridgePolynomialChan(TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 bridgeConfig, int32 voltageExcitSource, float64 voltageExcitVal, float64 nominalBridgeResistance, const float64 forwardCoeffs[], uInt32 numForwardCoeffs, const float64 reverseCoeffs[], uInt32 numReverseCoeffs, int32 electricalUnits, int32 physicalUnits, const char customScaleName[]);

Purpose

Creates channel(s) that use a Wheatstone bridge to measure torque.

Use this instance with sensors whose specifications provide a polynomial to convert electrical values to physical values.

When you use this scaling type, NI-DAQmx requires coefficients for a polynomial that converts electrical values to physical values (forward), as well as coefficients for a polynomial that converts physical values to electrical values (reverse). If you only know one set of coefficients, use the DAQmxCalculateReversePolyCoeff function to generate the other set.

Specify different values for units and physicalUnits if the sensor specifications provide physical values in one unit, but you want NI-DAQmx to scale data to a different unit.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 Specifies in which unit to return torque measurements from the channel.
Name Description
DAQmx_Val_NewtonMeters newton meters
DAQmx_Val_InchOunces ounce-inches
DAQmx_Val_InchPounds pound-inches
DAQmx_Val_FootPounds pound-feet
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
bridgeConfig int32 Specifies the Wheatstone bridge configuration connected to the channel.
Value Description
DAQmx_Val_FullBridge Four active sensing elements in the bridge
DAQmx_Val_HalfBridge Two active sensing elements in the bridge
DAQmx_Val_QuarterBridge One active sensing element in the bridge
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
nominalBridgeResistance float64 Specifies in ohms the resistance of the bridge while not under load.
forwardCoeffs const float64 [] An array of coefficients for the polynomial that converts electrical values to physical values. Each element of the array corresponds to a term of the equation. For example, if index three of the array is 9, the fourth term of the equation is 9x^3.
numForwardCoeffs uInt32 The number of coefficients in the forwardCoeffs array.
reverseCoeffs const float64 [] An array of coefficients for the polynomial that converts physical values to electrical values. Each element of the array corresponds to a term of the equation. For example, if index three of the array is 9, the fourth term of the equation is 9x^3.
numReverseCoeffs uInt32 The number of coefficients in the reverseCoeffs array.
electricalUnits int32 Specifies from which electrical unit to scale data. Select the same unit that the sensor data sheet or calibration certificate uses for electrical values.
Value Description
DAQmx_Val_VoltsPerVolt volts per volt
DAQmx_Val_mVoltsPerVolt millivolts per volt
physicalUnits int32 Specifies to which physical units to scale electrical data. Select the same unit that the sensor data sheet or calibration certificate uses for physical values.
Value Description
DAQmx_Val_NewtonMeters newton meters
DAQmx_Val_InchOunces ounce-inches
DAQmx_Val_InchPounds pound-inches
DAQmx_Val_FootPounds pound-feet
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAITorqueBridgeTableChan

int32 DAQmxCreateAITorqueBridgeTableChan(TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 bridgeConfig, int32 voltageExcitSource, float64 voltageExcitVal, float64 nominalBridgeResistance, const float64 electricalVals[], uInt32 numElectricalVals, int32 electricalUnits, const float64 physicalVals[], uInt32 numPhysicalVals, int32 physicalUnits, const char customScaleName[]);

Purpose

Creates channel(s) that use a Wheatstone bridge to measure torque.

Use this instance with sensors whose specifications provide a table of electrical values and the corresponding physical values.

When you use this scaling type, NI-DAQmx performs linear scaling between each pair of electrical and physical values. The input limits specified with minVal and maxVal must fall within the smallest and largest physical values. For any data outside those endpoints, NI-DAQmx coerces that data to the endpoints.

Specify different values for units and physicalUnits if the sensor specifications provide physical values in one unit, but you want NI-DAQmx to scale data to a different unit.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 Specifies in which unit to return torque measurements from the channel.
Name Description
DAQmx_Val_NewtonMeters newton meters
DAQmx_Val_InchOunces ounce-inches
DAQmx_Val_InchPounds pound-inches
DAQmx_Val_FootPounds pound-feet
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
bridgeConfig int32 Specifies the Wheatstone bridge configuration connected to the channel.
Value Description
DAQmx_Val_FullBridge Four active sensing elements in the bridge
DAQmx_Val_HalfBridge Two active sensing elements in the bridge
DAQmx_Val_QuarterBridge One active sensing element in the bridge
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
nominalBridgeResistance float64 Specifies in ohms the resistance of the bridge while not under load.
electricalVals const float64 [] The array of electrical values that map to the values in physicalVals. Specify this value in the unit indicated by electricalUnits.
numElectricalVals uInt32 The number of electrical values in the electricalVals array.
electricalUnits int32 Specifies from which electrical unit to scale data. Select the same unit that the sensor data sheet or calibration certificate uses for electrical values.
Value Description
DAQmx_Val_VoltsPerVolt volts per volt
DAQmx_Val_mVoltsPerVolt millivolts per volt
physicalVals const float64 [] The array of physical values that map to the values in electricalVals. Specify this value in the unit indicated by physicalUnits.
numPhysicalVals uInt32 The number of physical values in the physicalVals array.
physicalUnits int32 Specifies to which physical units to scale electrical data. Select the same unit that the sensor data sheet or calibration certificate uses for physical values.
Value Description
DAQmx_Val_NewtonMeters newton meters
DAQmx_Val_InchOunces ounce-inches
DAQmx_Val_InchPounds pound-inches
DAQmx_Val_FootPounds pound-feet
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAITorqueBridgeTwoPointLinChan

int32 DAQmxCreateAITorqueBridgeTwoPointLinChan(TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 bridgeConfig, int32 voltageExcitSource, float64 voltageExcitVal, float64 nominalBridgeResistance, float64 firstElectricalVal, float64 secondElectricalVal, int32 electricalUnits, float64 firstPhysicalVal, float64 secondPhysicalVal, int32 physicalUnits, const char customScaleName[]);

Purpose

Creates channel(s) that use a Wheatstone bridge to measure torque.

Use this instance with sensors whose specifications do not provide a polynomial for scaling or a table of electrical and physical values.

When you use this scaling type, NI-DAQmx uses two points of electrical and physical values to calculate the slope and y-intercept of a linear equation and uses that equation to scale electrical values to physical values.

Specify different values for units and physicalUnits if the sensor specifications provide physical values in one unit, but you want NI-DAQmx to scale data to a different unit.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 Specifies in which unit to return torque measurements from the channel.
Name Description
DAQmx_Val_NewtonMeters newton meters
DAQmx_Val_InchOunces ounce-inches
DAQmx_Val_InchPounds pound-inches
DAQmx_Val_FootPounds pound-feet
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
bridgeConfig int32 Specifies the Wheatstone bridge configuration connected to the channel.
Value Description
DAQmx_Val_FullBridge Four active sensing elements in the bridge
DAQmx_Val_HalfBridge Two active sensing elements in the bridge
DAQmx_Val_QuarterBridge One active sensing element in the bridge
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
nominalBridgeResistance float64 Specifies in ohms the resistance of the bridge while not under load.
firstElectricalVal float64 The first electrical value, corresponding to firstPhysicalVal. Specify this value in the unit indicated by electricalUnits.
secondElectricalVal float64 The second electrical value, corresponding to secondPhysicalVal. Specify this value in the unit indicated by electricalUnits.
electricalUnits int32 Specifies from which electrical unit to scale data. Select the same unit that the sensor data sheet or calibration certificate uses for electrical values.
Value Description
DAQmx_Val_VoltsPerVolt volts per volt
DAQmx_Val_mVoltsPerVolt millivolts per volt
firstPhysicalVal float64 The first physical value, corresponding to firstElectricalVal. Specify this value in the unit indicated by physicalUnits.
secondPhysicalVal float64 The second physical value, corresponding to secondElectricalValue. Specify this value in the unit indicated by physicalUnits.
physicalUnits int32 Specifies to which physical units to scale electrical data. Select the same unit that the sensor data sheet or calibration certificate uses for physical values.
Value Description
DAQmx_Val_NewtonMeters newton meters
DAQmx_Val_InchOunces ounce-inches
DAQmx_Val_InchPounds pound-inches
DAQmx_Val_FootPounds pound-feet
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIVelocityIEPEChan

int32 DAQmxCreateAIVelocityIEPEChan(TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], int32 terminalConfig, float64 minVal, float64 maxVal, int32 units, float64 sensitivity, int32 sensitivityUnits, int32 currentExcitSource, float64 currentExcitVal, const char customScaleName[]);

Purpose

Creates channel(s) that use an IEPE velocity sensor to measure velocity.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
terminalConfig int32 The input terminal configuration for the channel.
Value Description
DAQmx_Val_Cfg_Default At run time, NI-DAQmx chooses the default terminal configuration for the channel.
DAQmx_Val_RSE Referenced single-ended mode
DAQmx_Val_NRSE Non-referenced single-ended mode
DAQmx_Val_Diff Differential mode
DAQmx_Val_PseudoDiff Pseudodifferential mode
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 Specifies in which unit to return velocity measurements from the channel.
Value Description
DAQmx_Val_MetersPerSecond Meters per second.
DAQmx_Val_InchesPerSecond Inches per second.
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
sensitivity float64 The sensitivity of the sensor. This value is in the units you specify with the sensitivityUnits input. Refer to the sensor documentation to determine this value.
sensitivityUnits int32 The units of sensitivity.
Name Description
DAQmx_Val_MillivoltsPerMillimeterPerSecond mVolts/mm/s.
DAQmx_Val_MilliVoltsPerInchPerSecond mVolts/in/s.
currentExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel. You cannot use this value if the sensor requires excitation.
currentExcitVal float64 The amount of excitation, in amperes, that the sensor requires.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIVoltageChan

int32 DAQmxCreateAIVoltageChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], int32 terminalConfig, float64 minVal, float64 maxVal, int32 units, const char customScaleName[]);

Purpose

Creates channel(s) to measure voltage and adds the channel(s) to the task you specify with taskHandle. If your measurement requires the use of internal excitation or you need the voltage to be scaled by excitation, call DAQmxCreateAIVoltageChanWithExcit.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
terminalConfig int32 The input terminal configuration for the channel.
Value Description
DAQmx_Val_Cfg_Default At run time, NI-DAQmx chooses the default terminal configuration for the channel.
DAQmx_Val_RSE Referenced single-ended mode
DAQmx_Val_NRSE Non-referenced single-ended mode
DAQmx_Val_Diff Differential mode
DAQmx_Val_PseudoDiff Pseudodifferential mode
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the voltage measurements.
Name Description
DAQmx_Val_Volts volts
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIVoltageRMSChan

int32 DAQmxCreateAIVoltageRMSChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], int32 terminalConfig, float64 minVal, float64 maxVal, int32 units, const char customScaleName[]);

Purpose

Creates channel(s) to measure RMS voltage and adds the channel(s) to the task you specify with taskHandle. If your measurement requires the use of internal excitation or you need the voltage to be scaled by excitation, call DAQmxCreateAIVoltageChanWithExcit.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
terminalConfig int32 The input terminal configuration for the channel.
Value Description
DAQmx_Val_Cfg_Default At run time, NI-DAQmx chooses the default terminal configuration for the channel.
DAQmx_Val_RSE Referenced single-ended mode
DAQmx_Val_NRSE Non-referenced single-ended mode
DAQmx_Val_Diff Differential mode
DAQmx_Val_PseudoDiff Pseudodifferential mode
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the voltage measurements.
Name Description
DAQmx_Val_Volts volts
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIVoltageChanWithExcit

int32 DAQmxCreateAIVoltageChanWithExcit (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], int32 terminalConfig, float64 minVal, float64 maxVal, int32 units, int32 bridgeConfig, int32 voltageExcitSource, float64 voltageExcitVal, bool32 useExcitForScaling, const char customScaleName[]);

Purpose

Creates channel(s) to measure voltage and adds the channels to the task you specify with taskHandle. Use this instance for custom sensors that require excitation. You can choose to use the excitation to scale the measurement.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
terminalConfig int32 The input terminal configuration for the channel.
Value Description
DAQmx_Val_Cfg_Default At run time, NI-DAQmx chooses the default terminal configuration for the channel.
DAQmx_Val_RSE Referenced single-ended mode
DAQmx_Val_NRSE Non-referenced single-ended mode
DAQmx_Val_Diff Differential mode
DAQmx_Val_PseudoDiff Pseudodifferential mode
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the voltage measurements.
Name Description
DAQmx_Val_Volts volts
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
bridgeConfig int32 The type of Wheatstone bridge the sensor is.
Value Description
DAQmx_Val_FullBridge Sensor is a full bridge. If you set useExcitForScaling to TRUE, NI-DAQmx divides the measurement by the excitation value. Many sensors scale data to native units using scaling of volts per excitation.
DAQmx_Val_HalfBridge Sensor is a half bridge. If you set useExcitForScaling to TRUE, NI-DAQmx divides the measurement by the excitation value. Many sensors scale data to native units using scaling of volts per excitation.
DAQmx_Val_QuarterBridge Sensor is a quarter bridge. If you set useExcitForScaling to TRUE, NI-DAQmx divides the measurement by the excitation value. Many sensors scale data to native units using scaling of volts per excitation.
DAQmx_Val_NoBridge Sensor is not a Wheatstone bridge.
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
useExcitForScaling bool32 Specifies whether NI-DAQmx divides the measurement by the excitation. You should typically set useExcitForScaling to TRUE for ratiometric transducers. If you set useExcitForScaling to TRUE, set maxVal and minVal to reflect the scaling.
For example, if you expect to acquire a voltage between -5 and 5, and you use an excitation of .10 volts to scale the measurement, set minVal to -50 and set maxVal to 50. If you set bridgeConfig to DAQmx_Val_NoBridge, useExcitForScaling has no effect on the measurement.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIPosEddyCurrProxProbeChan

int32 DAQmxCreateAIPosEddyCurrProxProbeChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, float64 sensitivity, int32 sensitivityUnits, const char customScaleName[]);

Purpose

Creates channel(s) that use an [eddy current proximity probe](javascript:LaunchHelp('daqhelp.chm', 'EddyCurrentProximityProbe.html')) to measure linear position and adds the channel(s) to the task you specify with taskHandle.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return linear position measurements from the channel.
Name Description
DAQmx_Val_Meters Meters
DAQmx_Val_Inches Inches
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
sensitivity float64 The sensitivity of the sensor. This value is in the units you specify with the sensitivityUnits input. Refer to the sensor documentation to determine this value.
sensitivityUnits int32 The units of sensitivity.
Name Description
DAQmx_Val_mVoltsPerMil mVolts/mil
DAQmx_Val_VoltsPerMil Volts/mil
DAQmx_Val_mVoltsPerMillimeter mVolts/mMeter
DAQmx_Val_VoltsPerMillimeter Volts/mMeter
DAQmx_Val_mVoltsPerMicron mVolts/micron
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIPosLVDTChan

int32 DAQmxCreateAIPosLVDTChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, float64 sensitivity, int32 sensitivityUnits, int32 voltageExcitSource, float64 voltageExcitVal, float64 voltageExcitFreq, int32 ACExcitWireMode, const char customScaleName[]);

Purpose

Creates channel(s) that use an LVDT to measure linear position and adds the channel(s) to the task you specify with taskHandle.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return linear position measurements from the channel.
Name Description
DAQmx_Val_Meters Meters
DAQmx_Val_Inches Inches
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
sensitivity float64 The sensitivity of the sensor. This value is in the units you specify with the sensitivityUnits input. Refer to the sensor documentation to determine this value.
sensitivityUnits int32 The units of sensitivity.
Name Description
DAQmx_Val_mVoltsPerVoltPerMillimeter mvolts/volt/mmeter
DAQmx_Val_mVoltsPerVoltPerMilliInch mvolts/volt/0.001 inch
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
voltageExcitFreq float64 The excitation frequency, in hertz, that the sensor requires. Refer to the sensor documentation to determine this value.
ACExcitWireMode int32 The number of leads on the sensor. Some sensors may require you to tie leads together to create a 4-wire, 5-wire, or 6-wire sensor. Refer to the documentation for your sensor for more information.
Value Description
DAQmx_Val_4Wire 4-wire.
DAQmx_Val_5Wire 5-wire.
DAQmx_Val_6Wire 6-wire.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAIPosRVDTChan

int32 DAQmxCreateAIPosRVDTChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, float64 sensitivity, int32 sensitivityUnits, int32 voltageExcitSource, float64 voltageExcitVal, float64 voltageExcitFreq, int32 ACExcitWireMode, const char customScaleName[]);

Purpose

Creates channel(s) that use an RVDT to measure angular position and adds the channel(s) to the task you specify with taskHandle.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return angular position measurements from the channel.
Name Description
DAQmx_Val_Degrees Degrees
DAQmx_Val_Radians Radians
DAQmx_Val_FromCustomScale Units specified by a custom scale. Use customScaleName to specify a custom scale.
sensitivity float64 The sensitivity of the sensor. This value is in the units you specify with the sensitivityUnits input. Refer to the sensor documentation to determine this value.
sensitivityUnits int32 The units of sensitivity.
Name Description
DAQmx_Val_mVoltsPerVoltPerDegree mvolts/volt/degree
DAQmx_Val_mVoltsPerVoltPerRadian mvolts/volt/radian
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
voltageExcitFreq float64 The excitation frequency, in hertz, that the sensor requires. Refer to the sensor documentation to determine this value.
ACExcitWireMode int32 The number of leads on the sensor. Some sensors may require you to tie leads together to create a 4-wire, 5-wire, or 6-wire sensor. Refer to the documentation for your sensor for more information.
Value Description
DAQmx_Val_4Wire 4-wire.
DAQmx_Val_5Wire 5-wire.
DAQmx_Val_6Wire 6-wire.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

Obsolete

This function is obsolete. Use DAQmxCreateAITempBuiltInSensorChan instead.

Create TEDS Analog Input Channels

DAQmxCreateTEDSAIAccelChan

int32 DAQmxCreateTEDSAIAccelChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], int32 terminalConfig, float64 minVal, float64 maxVal, int32 units, int32 currentExcitSource, float64 currentExcitVal, const char customScaleName[]);

Purpose

Creates channel(s) that use an accelerometer to measure acceleration and adds the channel(s) to the task you specify with taskHandle. You must configure the physical channel(s) with TEDS information to use this function.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task used in this function.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
terminalConfig int32 The input terminal configuration for the channel.
Value Description
DAQmx_Val_Cfg_Default At run time, NI-DAQmx chooses the default terminal configuration for the channel.
DAQmx_Val_RSE Referenced single-ended mode
DAQmx_Val_NRSE Non-referenced single-ended mode
DAQmx_Val_Diff Differential mode
DAQmx_Val_PseudoDiff Pseudodifferential mode
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return acceleration measurements from the channel.
Name Description
DAQmx_Val_AccelUnit_g G-force (g). 1 g is approximately equal to 9.81 m/s2.
DAQmx_Val_FromCustomScale Units specified by a custom scale. Use customScaleName to specify a custom scale.
currentExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel. You cannot use this value if the sensor requires excitation.
currentExcitVal float64 The amount of excitation, in amperes, that the sensor requires.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateTEDSAICurrentChan

int32 DAQmxCreateTEDSAICurrentChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], int32 terminalConfig, float64 minVal, float64 maxVal, int32 units, int32 shuntResistorLoc, float64 externalShuntResistorValue, const char customScaleName[]);

Purpose

Creates channel(s) to measure current and adds the channel(s) to the task you specify with taskHandle. You must configure the physical channel(s) with TEDS information to use this function.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task used in this function.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
terminalConfig int32 The input terminal configuration for the channel.
Value Description
DAQmx_Val_Cfg_Default At run time, NI-DAQmx chooses the default terminal configuration for the channel.
DAQmx_Val_RSE Referenced single-ended mode
DAQmx_Val_NRSE Non-referenced single-ended mode
DAQmx_Val_Diff Differential mode
DAQmx_Val_PseudoDiff Pseudodifferential mode
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return measurements.
Name Description
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
DAQmx_Val_FromTEDS Units defined by TEDS information associated with the channel.
shuntResistorLoc int32 The location of the shunt resistor.
Value Description
DAQmx_Val_Internal Use the built-in shunt resistor of the device.
DAQmx_Val_External Use a shunt resistor external to the device. You must specify the value of the shunt resistor in extShuntResistorVal.
extShuntResistorVal float64 The value, in ohms, of an external shunt resistor.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateTEDSAIBridgeChan

int32 DAQmxCreateTEDSAIBridgeChan(TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 voltageExcitSource, float64 voltageExcitVal, const char customScaleName[]);

Purpose

Creates a channel that measures voltage ratios from a Wheatstone bridge.

You must configure the physical channel(s) with TEDS information to use this function.

Use this instance with bridge-based sensors that measure phenomena other than strain, force, pressure, or torque, or that scale data to physical units NI-DAQmx does not support.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 Specifies in which unit to return measurements from the channel.
Name Description
DAQmx_Val_FromTEDS Units defined by TEDS information associated with the channel.
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateTEDSAIForceBridgeChan

int32 DAQmxCreateTEDSAIForceBridgeChan(TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 voltageExcitSource, float64 voltageExcitVal, const char customScaleName[]);

Purpose

Creates channel(s) that use a Wheatstone bridge to measure force or load.

You must configure the physical channel(s) with TEDS information to use this function. NI-DAQmx scales electrical values to physical values according to that TEDS information.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 Specifies in which unit to return force measurements from the channel.
Name Description
DAQmx_Val_Newtons newtons
DAQmx_Val_Pounds pounds
DAQmx_Val_KilogramForce kilograms-force
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateTEDSAIForceIEPEChan

int32 DAQmxCreateTEDSAIForceIEPEChan(TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], int32 terminalConfig, float64 minVal, float64 maxVal, int32 units, int32 currentExcitSource, float64 currentExcitVal, const char customScaleName[]);

Purpose

Creates channel(s) that use an IEPE force sensor to measure force or load. You must configure the physical channel(s) with TEDS information to use this function.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
terminalConfig int32 The input terminal configuration for the channel.
Value Description
DAQmx_Val_Cfg_Default At run time, NI-DAQmx chooses the default terminal configuration for the channel.
DAQmx_Val_RSE Referenced single-ended mode
DAQmx_Val_NRSE Non-referenced single-ended mode
DAQmx_Val_Diff Differential mode
DAQmx_Val_PseudoDiff Pseudodifferential mode
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 Specifies in which unit to return force measurements from the channel.
Name Description
DAQmx_Val_Newtons newtons
DAQmx_Val_Pounds pounds
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
currentExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel. You cannot use this value if the sensor requires excitation.
currentExcitVal float64 The amount of excitation, in amperes, that the sensor requires.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateTEDSAIMicrophoneChan

int32 DAQmxCreateTEDSAIMicrophoneChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], int32 terminalConfig, int32 units, float64 maxSndPressLevel, int32 currentExcitSource, float64 currentExcitVal, const char customScaleName[]);

Purpose

Creates channel(s) that use a microphone to measure sound pressure and adds the channel(s) to the task you specify with taskHandle. You must configure the physical channel(s) with TEDS information to use this function.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task used in this function.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
terminalConfig int32 The input terminal configuration for the channel.
Value Description
DAQmx_Val_Cfg_Default At run time, NI-DAQmx chooses the default terminal configuration for the channel.
DAQmx_Val_RSE Referenced single-ended mode
DAQmx_Val_NRSE Non-referenced single-ended mode
DAQmx_Val_Diff Differential mode
DAQmx_Val_PseudoDiff Pseudodifferential mode
units int32 The units to use to return sound pressure measurements.
Name Description
DAQmx_Val_Pascals pascals
DAQmx_Val_FromCustomScale Units specified by a custom scale. Use customScaleName to specify a custom scale.
maxSndPressLevel float64 The maximum instantaneous sound pressure level you expect to measure. This value is in decibels, referenced to 20 micropascals.
currentExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel. You cannot use this value if the sensor requires excitation.
currentExcitVal float64 The amount of excitation, in amperes, that the sensor requires.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateTEDSAIPressureBridgeChan

int32 DAQmxCreateTEDSAIPressureBridgeChan(TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 voltageExcitSource, float64 voltageExcitVal, const char customScaleName[]);

Purpose

Creates channel(s) that use a Wheatstone bridge to measure pressure.

You must configure the physical channel(s) with TEDS information to use this function. NI-DAQmx scales electrical values to physical values according to that TEDS information.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 Specifies in which unit to return pressure measurements from the channel.
Name Description
DAQmx_Val_PoundsPerSquareInch pounds per square inch
DAQmx_Val_Bar bar
DAQmx_Val_Pascals pascals
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateTEDSAIResistanceChan

int32 DAQmxCreateTEDSAIResistanceChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 resistanceConfig, int32 currentExcitSource, float64 currentExcitVal, const char customScaleName[]);

Purpose

Creates channel(s) to measure resistance and adds the channel(s) to the task you specify with taskHandle. You must configure the physical channel(s) with TEDS information to use this function.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task used in this function.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return measurements.
Name Description
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
DAQmx_Val_FromTEDS Units defined by TEDS information associated with the channel.
resistanceConfig int32 The configuration for resistance measurements.
Value Description
DAQmx_Val_2Wire 2-wire mode.
DAQmx_Val_3Wire 3-wire mode.
DAQmx_Val_4Wire 4-wire mode.
currentExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel. You cannot use this value if the sensor requires excitation.
currentExcitVal float64 The amount of excitation, in amperes, that the sensor requires.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateTEDSAIRTDChan

int32 DAQmxCreateTEDSAIRTDChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 resistanceConfig, int32 currentExcitSource, float64 currentExcitVal);

Purpose

Creates channel(s) that use an RTD to measure temperature and adds the channel(s) to the task you specify with taskHandle. You must configure the physical channel(s) with TEDS information to use this function.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task used in this function.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the measurement.
Name Description
DAQmx_Val_DegC degrees Celsius
DAQmx_Val_DegF degrees Fahrenheit
DAQmx_Val_Kelvins kelvins
DAQmx_Val_DegR degrees Rankine
resistanceConfig int32 The configuration for resistance measurements.
Value Description
DAQmx_Val_2Wire 2-wire mode.
DAQmx_Val_3Wire 3-wire mode.
DAQmx_Val_4Wire 4-wire mode.
currentExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel. You cannot use this value if the sensor requires excitation.
currentExcitVal float64 The amount of excitation, in amperes, that the sensor requires.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateTEDSAIStrainGageChan

int32 DAQmxCreateTEDSAIStrainGageChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 voltageExcitSource, float64 voltageExcitVal, float64 initialBridgeVoltage, float64 leadWireResistance, const char customScaleName[]);

Purpose

Creates channel(s) to measure strain and adds the channel(s) to the task you specify with taskHandle. You must configure the physical channel(s) with TEDS information to use this function.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task used in this function.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the measurement.
Name Description
DAQmx_Val_Strain Strain
DAQmx_Val_FromCustomScale Units specified by a custom scale. Use customScaleName to specify a custom scale.
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
initialBridgeVoltage float64 The bridge output voltage in the unloaded condition. NI-DAQmx subtracts this value from any measurements before applying scaling equations. Perform a voltage measurement on the bridge with no strain applied to determine this value.
leadWireResistance float64 The amount, in ohms, of resistance in the lead wires. Ideally, this value is the same for all leads.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateTEDSAIThrmcplChan

int32 DAQmxCreateTEDSAIThrmcplChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 cjcSource, float64 cjcVal, const char cjcChannel[]);

Purpose

Creates channel(s) that use a thermocouple to measure temperature and adds the channel(s) to the task you specify with taskHandle. You must configure the physical channel(s) with TEDS information to use this function.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task used in this function.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the measurement.
Name Description
DAQmx_Val_DegC degrees Celsius
DAQmx_Val_DegF degrees Fahrenheit
DAQmx_Val_Kelvins kelvins
DAQmx_Val_DegR degrees Rankine
cjcSource int32 The source of cold junction compensation.
Value Description
DAQmx_Val_BuiltIn Use a cold-junction compensation channel built into the terminal block.
DAQmx_Val_ConstVal You must specify the cold-junction temperature.
DAQmx_Val_Chan Use a channel for cold-junction compensation.
cjcVal float64 The temperature of the cold junction of the thermocouple if you set cjcSource to DAQmx_Val_ConstVal.
cjcChannel const char [] The channel that acquires the temperature of the thermocouple cold-junction if you set cjcSource to DAQmx_Val_Chan. You can use a global channel or another virtual channel already in the task. If the channel is a temperature channel, NI-DAQmx acquires the temperature in the correct units. Other channel types, such as a resistance channel with a custom sensor, must use a custom scale to scale values to degrees Celsius.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateTEDSAIThrmstrChanIex

int32 DAQmxCreateTEDSAIThrmstrChanIex (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 resistanceConfig, int32 currentExcitSource, float64 currentExcitVal);

Purpose

Creates channel(s) that use a thermistor to measure temperature and adds the channel(s) to the task you specify with taskHandle. Use this instance when the thermistor requires current excitation. You must configure the physical channel(s) with TEDS information to use this function.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task used in this function.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the measurement.
Name Description
DAQmx_Val_DegC degrees Celsius
DAQmx_Val_DegF degrees Fahrenheit
DAQmx_Val_Kelvins kelvins
DAQmx_Val_DegR degrees Rankine
resistanceConfig int32 The configuration for resistance measurements.
Value Description
DAQmx_Val_2Wire 2-wire mode.
DAQmx_Val_3Wire 3-wire mode.
DAQmx_Val_4Wire 4-wire mode.
currentExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. You must use currentExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel. You cannot use this value if the sensor requires excitation.
currentExcitVal float64 The amount of excitation, in amperes, that the sensor requires.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateTEDSAIThrmstrChanVex

int32 DAQmxCreateTEDSAIThrmstrChanVex (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 resistanceConfig, int32 voltageExcitSource, float64 voltageExcitVal, float64 r1);

Purpose

Creates channel(s) that use a thermistor to measure temperature and adds the channel(s) to the task you specify with taskHandle. Use this instance when the thermistor requires voltage excitation. You must configure the physical channel(s) with TEDS information to use this function.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task used in this function.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the measurement.
Name Description
DAQmx_Val_DegC degrees Celsius
DAQmx_Val_DegF degrees Fahrenheit
DAQmx_Val_Kelvins kelvins
DAQmx_Val_DegR degrees Rankine
resistanceConfig int32 The configuration for resistance measurements.
Value Description
DAQmx_Val_2Wire 2-wire mode.
DAQmx_Val_3Wire 3-wire mode.
DAQmx_Val_4Wire 4-wire mode.
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
r1 float64 The value, in ohms, of the reference resistor.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateTEDSAITorqueBridgeChan

int32 DAQmxCreateTEDSAITorqueBridgeChan(TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 voltageExcitSource, float64 voltageExcitVal, const char customScaleName[]);

Purpose

Creates channel(s) that use a Wheatstone bridge to measure torque.

You must configure the physical channel(s) with TEDS information to use this function. NI-DAQmx scales electrical values to physical values according to that TEDS information.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 Specifies in which unit to return torque measurements from the channel.
Name Description
DAQmx_Val_NewtonMeters newton meters
DAQmx_Val_InchOunces ounce-inches
DAQmx_Val_InchPounds pound-inches
DAQmx_Val_FootPounds pound-feet
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateTEDSAIVoltageChan

int32 DAQmxCreateTEDSAIVoltageChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], int32 terminalConfig, float64 minVal, float64 maxVal, int32 units, const char customScaleName[]);

Purpose

Creates channel(s) to measure voltage and adds the channel(s) to the task you specify with taskHandle. You must configure the physical channel(s) with TEDS information to use this function. If your measurement requires the use of internal excitation or you need the voltage to be scaled by the excitation, use the DAQmxCreateTEDSAIVoltageChanWithExcit function.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task used in this function.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
terminalConfig int32 The input terminal configuration for the channel.
Value Description
DAQmx_Val_Cfg_Default At run time, NI-DAQmx chooses the default terminal configuration for the channel.
DAQmx_Val_RSE Referenced single-ended mode
DAQmx_Val_NRSE Non-referenced single-ended mode
DAQmx_Val_Diff Differential mode
DAQmx_Val_PseudoDiff Pseudodifferential mode
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return measurements.
Name Description
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
DAQmx_Val_FromTEDS Units defined by TEDS information associated with the channel.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateTEDSAIVoltageChanWithExcit

int32 DAQmxCreateTEDSAIVoltageChanWithExcit (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], int32 terminalConfig, float64 minVal, float64 maxVal, int32 units, int32 voltageExcitSource, float64 voltageExcitVal, const char customScaleName[]);

Purpose

Creates channel(s) to measure voltage and adds the channel(s) to the task you specify with taskHandle. Use this instance for custom sensors that require excitation. You can use the excitation to scale the measurement. You must configure the physical channel(s) with TEDS information to use this function.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task used in this function.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
terminalConfig int32 The input terminal configuration for the channel.
Value Description
DAQmx_Val_Cfg_Default At run time, NI-DAQmx chooses the default terminal configuration for the channel.
DAQmx_Val_RSE Referenced single-ended mode
DAQmx_Val_NRSE Non-referenced single-ended mode
DAQmx_Val_Diff Differential mode
DAQmx_Val_PseudoDiff Pseudodifferential mode
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return measurements.
Name Description
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
DAQmx_Val_FromTEDS Units defined by TEDS information associated with the channel.
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateTEDSAIPosLVDTChan

int32 DAQmxCreateTEDSAIPosLVDTChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 voltageExcitSource, float64 voltageExcitVal, float64 voltageExcitFreq, int32 ACExcitWireMode, const char customScaleName[]);

Purpose

Creates channel(s) that use an LVDT to measure linear position and adds the channel(s) to the task you specify with taskHandle. You must configure the physical channel(s) with TEDS information to use this function.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task used in this function.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return linear position measurements from the channel.
Name Description
DAQmx_Val_Meters Meters
DAQmx_Val_Inches Inches
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
voltageExcitFreq float64 The excitation frequency, in hertz, that the sensor requires. Refer to the sensor documentation to determine this value.
ACExcitWireMode int32 The number of leads on the sensor. Some sensors may require you to tie leads together to create a 4-wire, 5-wire, or 6-wire sensor. Refer to the documentation for your sensor for more information.
Value Description
DAQmx_Val_4Wire 4-wire.
DAQmx_Val_5Wire 5-wire.
DAQmx_Val_6Wire 6-wire.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateTEDSAIPosRVDTChan

int32 DAQmxCreateTEDSAIPosRVDTChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 voltageExcitSource, float64 voltageExcitVal, float64 voltageExcitFreq, int32 ACExcitWireMode, const char customScaleName[]);

Purpose

Creates channel(s) that use an RVDT to measure angular position and adds the channel(s) to the task you specify with taskHandle. You must configure the physical channel(s) with TEDS information to use this function.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task used in this function.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return angular position measurements from the channel.
Name Description
DAQmx_Val_Degrees Degrees
DAQmx_Val_Radians Radians
DAQmx_Val_FromCustomScale Units specified by a custom scale. Use customScaleName to specify a custom scale.
voltageExcitSource int32 The source of excitation.
Value Description
DAQmx_Val_Internal Use the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_External Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use voltageExcitVal to specify the amount of excitation.
DAQmx_Val_None Supply no excitation to the channel.
voltageExcitVal float64 Specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
voltageExcitFreq float64 The excitation frequency, in hertz, that the sensor requires. Refer to the sensor documentation to determine this value.
ACExcitWireMode int32 The number of leads on the sensor. Some sensors may require you to tie leads together to create a 4-wire, 5-wire, or 6-wire sensor. Refer to the documentation for your sensor for more information.
Value Description
DAQmx_Val_4Wire 4-wire.
DAQmx_Val_5Wire 5-wire.
DAQmx_Val_6Wire 6-wire.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

Create Analog Output Channel

DAQmxCreateAOCurrentChan

int32 DAQmxCreateAOCurrentChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, const char customScaleName[]);

Purpose

Creates channel(s) to generate current and adds the channel(s) to the task you specify with taskHandle.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to generate.
maxVal float64 The maximum value, in units, that you expect to generate.
units int32 The units in which to generate current.
Value Description
DAQmx_Val_Amps amperes
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAOFuncGenChan

int32 DAQmxCreateAOFuncGenChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], int32 type, float64 frequency, float64 amplitude, float64 offset);

Purpose

Creates a channel for continually generating a waveform on the selected physical channel.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
type int32 Specifies the kind of waveform to generate.
Value Description
DAQmx_Val_Sine Sine wave
DAQmx_Val_Triangle Triangle wave
DAQmx_Val_Square Sawtooth wave
DAQmx_Val_Sawtooth Square wave
frequency float64 The frequency of the waveform to generate in hertz.
amplitude float64 The zero-to-peak amplitude of the waveform to generate in volts. Zero and negative values are valid.
offset float64 The voltage offset of the waveform to generate.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateAOVoltageChan

int32 DAQmxCreateAOVoltageChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, const char customScaleName[]);

Purpose

Creates channel(s) to generate voltage and adds the channel(s) to the task you specify with taskHandle.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
physicalChannel const char [] The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to generate.
maxVal float64 The maximum value, in units, that you expect to generate.
units int32 The units in which to generate voltage.
Name Description
DAQmx_Val_Volts volts
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

Create Digital Input Channels

DAQmxCreateDIChan

int32 DAQmxCreateDIChan (TaskHandle taskHandle, const char lines[], const char nameToAssignToLines[], int32 lineGrouping);

Purpose

Creates channel(s) to measure digital signals and adds the channel(s) to the task you specify with taskHandle. You can group digital lines into one digital channel or separate them into multiple digital channels. If you specify one or more entire ports in lines by using port physical channel names, you cannot separate the ports into multiple channels. To separate ports into multiple channels, use this function multiple times with a different port each time.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
lines const char [] The names of the digital lines used to create a virtual channel. You can specify a list or range of lines. Specifying a port and no lines is the equivalent of specifying all the lines of that port in order. Therefore, if you specify Dev1/port0 and port 0 has eight lines, this is expanded to Dev1/port0/line0:7.
nameToAssignToLines const char [] The name of the created virtual channel(s). If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToLines, you must use the names when you refer to these channels in other NI-DAQmx functions.
lineGrouping int32 Specifies whether to group digital lines into one or more virtual channels. If you specify one or more entire ports in lines, you must set lineGrouping to DAQmx_Val_ChanForAllLines.
Value Description
DAQmx_Val_ChanPerLine One channel for each line
DAQmx_Val_ChanForAllLines One channel for all lines

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

Create Digital Output Channels

DAQmxCreateDOChan

int32 DAQmxCreateDOChan (TaskHandle taskHandle, const char lines[], const char nameToAssignToLines[], int32 lineGrouping);

Purpose

Creates channel(s) to generate digital signals and adds the channel(s) to the task you specify with taskHandle. You can group digital lines into one digital channel or separate them into multiple digital channels. If you specify one or more entire ports in lines by using port physical channel names, you cannot separate the ports into multiple channels. To separate ports into multiple channels, use this function multiple times with a different port each time.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
lines const char [] The names of the digital lines used to create a virtual channel. You can specify a list or range of lines. Specifying a port and no lines is the equivalent of specifying all the lines of that port in order. Therefore, if you specify Dev1/port0 and port 0 has eight lines, this is expanded to Dev1/port0/line0:7.
nameToAssignToLines const char [] The name of the created virtual channel(s). If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToLines, you must use the names when you refer to these channels in other NI-DAQmx functions.
lineGrouping int32 Specifies whether to group digital lines into one or more virtual channels. If you specify one or more entire ports in lines, you must set lineGrouping to DAQmx_Val_ChanForAllLines.
Value Description
DAQmx_Val_ChanPerLine One channel for each line
DAQmx_Val_ChanForAllLines One channel for all lines

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

Create Counter Input Channels

DAQmxCreateCIAngVelocityChan

int32 DAQmxCreateCIAngVelocityChan (TaskHandle taskHandle, const char counter[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 decodingType, int32 units, uInt32 pulsesPerRev, const char customScaleName[]);

Purpose

Creates a channel to measure angular velocity. With the exception of devices that support multi-counter tasks, you can create only one counter input channel at a time with this function because a task can contain only one counter input channel. To read from multiple counters simultaneously, use a separate task for each counter. Connect the input signal to the default input terminal of the counter unless you select a different input terminal.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
counter const char [] The name of the counter to use to create virtual channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
decodingType int32 Specifies how to count and interpret the pulses that the encoder generates on signal A and signal B. DAQmx_Val_X1, DAQmx_Val_X2, and DAQmx_Val_X4 are valid for quadrature encoders only. DAQmx_Val_TwoPulseCounting is valid only for two-pulse encoders.
DAQmx_Val_X2 and DAQmx_Val_X4 decoding are more sensitive to smaller changes in position than DAQmx_Val_X1 encoding, with DAQmx_Val_X4 being the most sensitive. However, more sensitive decoding is more likely to produce erroneous measurements if there is vibration in the encoder or other noise in the signals.
Value Description
DAQmx_Val_X1 If signal A leads signal B, count the rising edges of signal A. If signal B leads signal A, count the falling edges of signal A.
DAQmx_Val_X2 Count the rising and falling edges of signal A.
DAQmx_Val_X4 Count the rising and falling edges of both signal A and signal B.
DAQmx_Val_TwoPulseCounting Increment the count on rising edges of signal A. Decrement the count on rising pulses of signal B.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 Specifies in which unit to return velocity measurements from the channel.
Value Description
DAQmx_Val_RPM Revolutions per minute.
DAQmx_Val_RadiansPerSecond Radians per second.
DAQmx_Val_DegreesPerSecond Degrees per second.
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
pulsesPerRev uInt32 The number of pulses the encoder generates per revolution. This value is the number of pulses on either signal A or signal B, not the total number of pulses on both signal A and signal B.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateCICountEdgesChan

int32 DAQmxCreateCICountEdgesChan (TaskHandle taskHandle, const char counter[], const char nameToAssignToChannel[], int32 edge, uInt32 initialCount, int32 countDirection);

Purpose

Creates a channel to count the number of rising or falling edges of a digital signal and adds the channel to the task you specify with taskHandle. With the exception of devices that support multi-counter tasks, you can create only one counter input channel at a time with this function because a task can contain only one counter input channel. To read from multiple counters simultaneously, use a separate task for each counter. Connect the input signal to the default input terminal of the counter unless you select a different input terminal.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
counter const char [] The name of the counter to use to create virtual channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
edge int32 Specifies on which edges of the input signal to increment or decrement the count.
Value Description
DAQmx_Val_Rising Rising edge(s).
DAQmx_Val_Falling Falling edge(s).
initialCount uInt32 The value from which to start counting.
countDirection int32 Specifies whether to increment or decrement the counter on each edge.
Value Description
DAQmx_Val_CountUp Increment the count register on each edge.
DAQmx_Val_CountDown Decrement the count register on each edge.
DAQmx_Val_ExtControlled The state of a digital line controls the count direction. Each counter has a default count direction terminal.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateCIDutyCycleChan

int32 DAQmxCreateCIDutyCycleChan (TaskHandle taskHandle, const char counter[], const char nameToAssignToChannel[], float64 minFreq, float64 maxFreq, int32 edge, const char customScaleName[]);

Purpose

Creates channel(s) to duty cycle of a digital pulse. Connect the input signal to the default input terminal of the counter unless you select a different input terminal. With the exception of devices that support multi-counter tasks, you can create only one counter input channel at a time with this function because a task can contain only one counter input channel. To read from multiple counters simultaneously, use a separate task for each counter.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
counter const char [] The name of the counter to use to create virtual channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
maxFreq float64 The maximum frequency you expect to measure.
minFreq float64 The minimum frequency you expect to measure.
edge int32 Specifies between which edges to measure the frequency or period of the signal.
Value Description
DAQmx_Val_Falling Measure between falling edges.
DAQmx_Val_Rising Measure between rising edges.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateCIFreqChan

int32 DAQmxCreateCIFreqChan (TaskHandle taskHandle, const char counter[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 edge, int32 measMethod, float64 measTime, uInt32 divisor, const char customScaleName[]);

Purpose

Creates a channel to measure the frequency of a digital signal and adds the channel to the task you specify with taskHandle. With the exception of devices that support multi-counter tasks, you can create only one counter input channel at a time with this function because a task can contain only one counter input channel. To read from multiple counters simultaneously, use a separate task for each counter. Connect the input signal to the default input terminal of the counter unless you select a different input terminal.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
counter const char [] The name of the counter to use to create virtual channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the measurement.
Name Description
DAQmx_Val_Hz hertz
DAQmx_Val_Ticks Timebase ticks
DAQmx_Val_FromCustomScale Units by a custom scale. Use customScaleName to specify a custom scale.
edge int32 Specifies between which edges to measure the frequency or period of the signal.
Value Description
DAQmx_Val_Rising Rising edge(s).
DAQmx_Val_Falling Falling edge(s).
measMethod int32 The method used to calculate the period or frequency of the signal.
Value Description
DAQmx_Val_LowFreq1Ctr Use one counter that uses a constant timebase to measure the input signal.
DAQmx_Val_HighFreq2Ctr Use two counters, one of which counts pulses of the signal to measure during the specified measurement time.
DAQmx_Val_LargeRng2Ctr Use one counter to divide the frequency of the input signal to create a lower-frequency signal that the second counter can more easily measure.
Caution Refer to [Quantization Error](javascript:LaunchHelp('daqhelp.chm', 'QuantError.html')) in the NI-DAQmx Help to choose a measurement method that will limit error in the frequency measurement.
measTime float64 The length of time to measure the frequency or period of a digital signal, when measMethod is DAQmx_Val_HighFreq2Ctr. Measurement accuracy increases with increased measurement time and with increased signal frequency.
Caution If you measure a high-frequency signal for too long a time, the count register could roll over, resulting in an incorrect measurement.
divisor uInt32 The value by which to divide the input signal, when measMethod is DAQmx_Val_LargeRng2Ctr. The larger this value, the more accurate the measurement, but too large a value can cause the count register to roll over, resulting in an incorrect measurement.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateCILinVelocityChan

int32 DAQmxCreateCILinVelocityChan (TaskHandle taskHandle, const char counter[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 decodingType, int32 units, float64 distPerPulse, const char customScaleName[]);

Purpose

Creates a channel that uses a linear encoder to measure linear velocity. With the exception of devices that support multi-counter tasks, you can create only one counter input channel at a time with this function because a task can contain only one counter input channel. To read from multiple counters simultaneously, use a separate task for each counter. Connect the input signal to the default input terminal of the counter unless you select a different input terminal.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
counter const char [] The name of the counter to use to create virtual channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
decodingType int32 Specifies how to count and interpret the pulses that the encoder generates on signal A and signal B. DAQmx_Val_X1, DAQmx_Val_X2, and DAQmx_Val_X4 are valid for quadrature encoders only. DAQmx_Val_TwoPulseCounting is valid only for two-pulse encoders.
DAQmx_Val_X2 and DAQmx_Val_X4 decoding are more sensitive to smaller changes in position than DAQmx_Val_X1 encoding, with DAQmx_Val_X4 being the most sensitive. However, more sensitive decoding is more likely to produce erroneous measurements if there is vibration in the encoder or other noise in the signals.
Value Description
DAQmx_Val_X1 If signal A leads signal B, count the rising edges of signal A. If signal B leads signal A, count the falling edges of signal A.
DAQmx_Val_X2 Count the rising and falling edges of signal A.
DAQmx_Val_X4 Count the rising and falling edges of both signal A and signal B.
DAQmx_Val_TwoPulseCounting Increment the count on rising edges of signal A. Decrement the count on rising pulses of signal B.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 Specifies in which unit to return velocity measurements from the channel.
Value Description
DAQmx_Val_MetersPerSecond Meters per second.
DAQmx_Val_InchesPerSecond Inches per second.
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
distPerPulse float64 The distance to measure for each pulse the encoder generates on signal A or signal B. This value is in the units specified with the units input.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateCIPeriodChan

int32 DAQmxCreateCIPeriodChan (TaskHandle taskHandle, const char counter[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 edge, int32 measMethod, float64 measTime, uInt32 divisor, const char customScaleName[]);

Purpose

Creates a channel to measure the period of a digital signal and adds the channel to the task you specify with taskHandle. With the exception of devices that support multi-counter tasks, you can create only one counter input channel at a time with this function because a task can contain only one counter input channel. To read from multiple counters simultaneously, use a separate task for each counter. Connect the input signal to the default input terminal of the counter unless you select a different input terminal.

Note When measMethod is set to DAQmx_Val_LowFreq1Ctr, you must pass the values 0.000001 for measTime and 4 for divisor. These values will be ignored by the function, but if they are not passed, the function returns an error.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
counter const char [] The name of the counter to use to create virtual channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the measurement.
Value Description
DAQmx_Val_Seconds seconds
DAQmx_Val_Ticks Timebase ticks
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
edge int32 Specifies between which edges to measure the frequency or period of the signal.
Value Description
DAQmx_Val_Rising Rising edge(s).
DAQmx_Val_Falling Falling edge(s).
measMethod int32 Specifies the method used to calculate the frequency or period of the signal.
Value Description
DAQmx_Val_LowFreq1Ctr Use one counter that uses a constant timebase to measure the input signal.
DAQmx_Val_HighFreq2Ctr Use two counters, one of which counts pulses of the signal to measure during the specified measurement time.
DAQmx_Val_LargeRng2Ctr Use one counter to divide the frequency of the input signal to create a lower-frequency signal that the second counter can more easily measure.
measTime float64 The length of time to measure the frequency or period of a digital signal, when measMethod is DAQmx_Val_HighFreq2Ctr. Measurement accuracy increases with increased measurement time and with increased signal frequency.
Caution If you measure a high-frequency signal for too long a time, the count register could roll over, resulting in an incorrect measurement.
divisor uInt32 The value by which to divide the input signal, when measMethod is DAQmx_Val_LargeRng2Ctr. The larger this value, the more accurate the measurement, but too large a value can cause the count register to roll over, resulting in an incorrect measurement.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateCIPulseChanFreq

int32 DAQmxCreateCIPulseChanFreq (TaskHandle taskHandle, const char counter[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units);

Purpose

Creates a channel to measure pulse specifications, returning the measurements as pairs of frequency and duty cycle, and adds the channel to the task you specify with taskHandle. With the exception of devices that support multi-counter tasks, you can create only one counter input channel at a time with this function because a task can contain only one counter input channel. To read from multiple counters simultaneously, use a separate task for each counter. Connect the input signal to the default input terminal of the counter unless you select a different input terminal.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
counter const char [] The name of the counter to use to create virtual channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the measurement.
Value Description
DAQmx_Val_Hz hertz

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateCIPulseChanTicks

int32 DAQmxCreateCIPulseChanTicks (TaskHandle taskHandle, const char counter[], const char nameToAssignToChannel[], const char sourceTerminal[], float64 minVal, float64 maxVal);

Purpose

Creates a channel to measure pulse specifications, returning the measurements as pairs of high ticks and low ticks, and adds the channel to the task you specify with taskHandle. With the exception of devices that support multi-counter tasks, you can create only one counter input channel at a time with this function because a task can contain only one counter input channel. To read from multiple counters simultaneously, use a separate task for each counter. Connect the input signal to the default input terminal of the counter unless you select a different input terminal.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
counter const char [] The name of the counter to use to create virtual channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
sourceTerminal const char [] The originating terminal of the route. You can specify a terminal name.
minVal float64 The minimum value that you expect to measure.
maxVal float64 The maximum value that you expect to measure.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateCIPulseChanTime

int32 DAQmxCreateCIPulseChanTime (TaskHandle taskHandle, const char counter[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units);

Purpose

Creates a channel to measure pulse specifications, returning the measurements as pairs of high time and low time, and adds the channel to the task you specify with taskHandle. With the exception of devices that support multi-counter tasks, you can create only one counter input channel at a time with this function because a task can contain only one counter input channel. To read from multiple counters simultaneously, use a separate task for each counter. Connect the input signal to the default input terminal of the counter unless you select a different input terminal.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
counter const char [] The name of the counter to use to create virtual channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the measurement.
Value Description
DAQmx_Val_Seconds seconds

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateCIPulseWidthChan

int32 DAQmxCreateCIPulseWidthChan (TaskHandle taskHandle, const char counter[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 startingEdge, const char customScaleName[]);

Purpose

Creates a channel to measure the width of a digital pulse and adds the channel to the task you specify with taskHandle. startingEdge determines whether to measure a high pulse or a low pulse. With the exception of devices that support multi-counter tasks, you can create only one counter input channel at a time with this function because a task can contain only one counter input channel. To read from multiple counters simultaneously, use a separate task for each counter. Connect the input signal to the default input terminal of the counter unless you select a different input terminal.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
counter const char [] The name of the counter to use to create virtual channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the measurement.
Value Description
DAQmx_Val_Seconds seconds
DAQmx_Val_Ticks Timebase ticks
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
startingEdge int32 Specifies on which edge to begin measuring pulse width.
Value Description
DAQmx_Val_Rising Rising edge(s).
DAQmx_Val_Falling Falling edge(s).
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateCISemiPeriodChan

int32 DAQmxCreateCISemiPeriodChan (TaskHandle taskHandle, const char counter[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, const char customScaleName[]);

Purpose

Creates a channel to measure the time between state transitions of a digital signal and adds the channel to the task you specify with taskHandle. With the exception of devices that support multi-counter tasks, you can create only one counter input channel at a time with this function because a task can contain only one counter input channel. To read from multiple counters simultaneously, use a separate task for each counter. Connect the input signal to the default input terminal of the counter unless you select a different input terminal.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
counter const char [] The name of the counter to use to create virtual channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the measurement.
Value Description
DAQmx_Val_Seconds seconds
DAQmx_Val_Ticks Timebase ticks
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateCITwoEdgeSepChan

DAQmxCreateCITwoEdgeSepChan (TaskHandle taskHandle, const char counter[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 firstEdge, int32 secondEdge, const char customScaleName[]);

Purpose

Creates a channel that measures the amount of time between the rising or falling edge of one digital signal and the rising or falling edge of another digital signal. With the exception of devices that support multi-counter tasks, you can create only one counter input channel at a time with this function because a task can contain only one counter input channel. To read from multiple counters simultaneously, use a separate task for each counter. Connect the input signals to the default input terminals of the counter unless you select different input terminals.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
counter const char [] The name of the counter to use to create virtual channels.
nameToAssignToChannel const char [] The name to assign to the created virtual channel. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
minVal float64 The minimum value, in units, that you expect to measure.
maxVal float64 The maximum value, in units, that you expect to measure.
units int32 The units to use to return the measurement.
Value Description
DAQmx_Val_Seconds seconds
DAQmx_Val_Ticks Timebase ticks
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
firstEdge int32 Specifies on which edge of the first signal to start each measurement.
Name Description
DAQmx_Val_Rising Start each measurement on the rising edge of the first signal.
DAQmx_Val_Falling Start each measurement on the falling edge of the first signal.
secondEdge int32 Specifies on which edge of the first signal to stop each measurement.
Name Description
DAQmx_Val_Rising Stop each measurement on the rising edge of the second signal.
DAQmx_Val_Falling Stop each measurement on the falling edge of the second signal.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateCILinEncoderChan

int32 DAQmxCreateCILinEncoderChan (TaskHandle taskHandle, const char counter[], const char nameToAssignToChannel[], int32 decodingType, bool32 ZidxEnable, float64 ZidxVal, int32 ZidxPhase, int32 units, float64 distPerPulse, float64 initialPos, const char customScaleName[]);

Purpose

Creates a channel that uses a linear encoder to measure linear position. With the exception of devices that support multi-counter tasks, you can create only one counter input channel at a time with this function because a task can contain only one counter input channel. To read from multiple counters simultaneously, use a separate task for each counter. Connect the input signals to the default input terminals of the counter unless you select different input terminals.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
counter const char [] The name of the counter to use to create virtual channels.
nameToAssignToChannel const char [] The name to assign to the created virtual channel. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
decodingType int32 Specifies how to count and interpret the pulses that the encoder generates on signal A and signal B. DAQmx_Val_X1, DAQmx_Val_X2, and DAQmx_Val_X4 are valid for quadrature encoders only. DAQmx_Val_TwoPulseCounting is valid only for two-pulse encoders.
DAQmx_Val_X2 and DAQmx_Val_X4 decoding are more sensitive to smaller changes in position than DAQmx_Val_X1 encoding, with DAQmx_Val_X4 being the most sensitive. However, more sensitive decoding is more likely to produce erroneous measurements if there is vibration in the encoder or other noise in the signals.
Value Description
DAQmx_Val_X1 If signal A leads signal B, count the rising edges of signal A. If signal B leads signal A, count the falling edges of signal A.
DAQmx_Val_X2 Count the rising and falling edges of signal A.
DAQmx_Val_X4 Count the rising and falling edges of both signal A and signal B.
DAQmx_Val_TwoPulseCounting Increment the count on rising edges of signal A. Decrement the count on rising pulses of signal B.
ZidxEnable bool32 Specifies whether to enable z indexing for the measurement.
ZidxVal float64 The value, in units, to which to reset the measurement when signal Z is high and signal A and signal B are at the states you specify with ZidxPhase.
ZidxPhase int32 The states at which signal A and signal B must be while signal Z is high for NI-DAQmx to reset the measurement. If signal Z is never high while the signal A and signal B are high, for example, you must choose a phase other than DAQmx_Val_AHighBHigh.
When signal Z goes high and how long it stays high varies from encoder to encoder. Refer to the documentation for the encoder to determine the timing of signal Z with respect to signal A and signal B.
Value Description
DAQmx_Val_AHighBHigh Reset the measurement when both signal A and signal B are at high logic.
DAQmx_Val_AHighBLow Reset the measurement when signal A is at high logic and signal B is at low logic.
DAQmx_Val_ALowBHigh Reset the measurement when signal A is at low logic and signal B is at high logic.
DAQmx_Val_ALowBLow Reset the measurement when both signal A and signal B are at low logic.
units int32 The units to use to return linear position measurements from the channel.
Name Description
DAQmx_Val_Meters Meters.
DAQmx_Val_Inches Inches.
DAQmx_Val_Ticks Timebase Ticks.
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
distPerPulse float64 The distance measured for each pulse the encoder generates. Specify this value in units.
initialPos float64 The position of the encoder when the measurement begins. This value is in units.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateCIAngEncoderChan

int32 DAQmxCreateCIAngEncoderChan (TaskHandle taskHandle, const char counter[], const char nameToAssignToChannel[], int32 decodingType, bool32 ZidxEnable, float64 ZidxVal, int32 ZidxPhase, int32 units, uInt32 pulsesPerRev, float64 initialAngle, const char customScaleName[]);

Purpose

Creates a channel that uses an angular encoder to measure angular position. With the exception of devices that support multi-counter tasks, you can create only one counter input channel at a time with this function because a task can contain only one counter input channel. To read from multiple counters simultaneously, use a separate task for each counter. Connect the input signals to the default input terminals of the counter unless you select different input terminals.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
counter const char [] The name of the counter to use to create virtual channels.
nameToAssignToChannel const char [] The name to assign to the created virtual channel. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
decodingType int32 Specifies how to count and interpret the pulses that the encoder generates on signal A and signal B. DAQmx_Val_X1, DAQmx_Val_X2, and DAQmx_Val_X4 are valid for quadrature encoders only. DAQmx_Val_TwoPulseCounting is valid only for two-pulse encoders.
DAQmx_Val_X2 and DAQmx_Val_X4 decoding are more sensitive to smaller changes in position than DAQmx_Val_X1 encoding, with DAQmx_Val_X4 being the most sensitive. However, more sensitive decoding is more likely to produce erroneous measurements if there is vibration in the encoder or other noise in the signals.
Value Description
DAQmx_Val_X1 If signal A leads signal B, count the rising edges of signal A. If signal B leads signal A, count the falling edges of signal A.
DAQmx_Val_X2 Count the rising and falling edges of signal A.
DAQmx_Val_X4 Count the rising and falling edges of both signal A and signal B.
DAQmx_Val_TwoPulseCounting Increment the count on rising edges of signal A. Decrement the count on rising pulses of signal B.
ZidxEnable bool32 Specifies whether to enable z indexing for the measurement.
ZidxVal float64 The value, in units, to which to reset the measurement when signal Z is high and signal A and signal B are at the states you specify with ZidxPhase.
ZidxPhase int32 The states at which signal A and signal B must be while signal Z is high for NI-DAQmx to reset the measurement. If signal Z is never high while the signal A and signal B are high, for example, you must choose a phase other than DAQmx_Val_AHighBHigh.
When signal Z goes high and how long it stays high varies from encoder to encoder. Refer to the documentation for the encoder to determine the timing of signal Z with respect to signal A and signal B.
Value Description
DAQmx_Val_AHighBHigh Reset the measurement when both signal A and signal B are at high logic.
DAQmx_Val_AHighBLow Reset the measurement when signal A is at high logic and signal B is at low logic.
DAQmx_Val_ALowBHigh Reset the measurement when signal A is at low logic and signal B is at high logic.
DAQmx_Val_ALowBLow Reset the measurement when both signal A and signal B are at low logic.
units int32 The units to use to return angular position measurements from the channel.
Value Description
DAQmx_Val_Degrees Degrees
DAQmx_Val_Radians Radians
DAQmx_Val_Ticks Timebase ticks
DAQmx_Val_FromCustomScale Units a custom scale specifies. Use customScaleName to specify a custom scale.
pulsesPerRev uInt32 The number of pulses the encoder generates per revolution. This value is the number of pulses on one of either A signal or B signal, not the total number of pulses on both signal A and signal B.
initialAngle float64 The starting angle of the encoder when the measurement begins. Specify this value in units.
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateCIGPSTimestampChan

int32 DAQmxCreateCIGPSTimestampChan (TaskHandle taskHandle, const char counter[], const char nameToAssignToChannel[], int32 units, int32 gpsSyncMethod, const char custScaleName[]);

Purpose

Creates a channel that uses a special-purpose counter to take a timestamp and synchronizes that counter to a GPS receiver. With the exception of devices that support multi-counter tasks, you can create only one counter input channel at a time with this function because a task can contain only one counter input channel. To read from multiple counters simultaneously, use a separate task for each counter. Connect the input signal to the default input terminal of the counter unless you select a different input terminal.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
counter const char [] The name of the counter to use to create virtual channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
units int32 The units to use to return the timestamp.
Value Description
DAQmx_Val_Seconds Seconds
DAQmx_Val_FromCustomScale From custom scale
gpsSyncMethod int32 The method to use to synchronize the counter to a GPS receiver.
Value Description
DAQmx_Val_IRIGB IRIG-B
DAQmx_Val_PPS PPS
DAQmx_Val_None None
customScaleName const char [] The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

Create Counter Output Channels

DAQmxCreateCOPulseChanFreq

int32 DAQmxCreateCOPulseChanFreq (TaskHandle taskHandle, const char counter[], const char nameToAssignToChannel[], int32 units, int32 idleState, float64 initialDelay, float64 freq, float64 dutyCycle);

Purpose

Creates channel(s) to generate digital pulses that freq and dutyCycle define and adds the channel to the task you specify with taskHandle. The pulses appear on the default output terminal of the counter unless you select a different output terminal.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
counter const char [] The name of the counter to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
units int32 The units in which to specify freq.
Name Description
DAQmx_Val_Hz hertz
idleState int32 The resting state of the output terminal.
Value Description
DAQmx_Val_High High state.
DAQmx_Val_Low Low state.
initialDelay float64 The amount of time in seconds to wait before generating the first pulse.
freq float64 The frequency at which to generate pulses.
dutyCycle float64 The width of the pulse divided by the pulse period. NI-DAQmx uses this ratio, combined with frequency, to determine pulse width and the interval between pulses.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateCOPulseChanTicks

int32 DAQmxCreateCOPulseChanTicks (TaskHandle taskHandle, const char counter[], const char nameToAssignToChannel[], const char sourceTerminal[], int32 idleState, int32 initialDelay, int32 lowTicks, int32 highTicks);

Purpose

Creates channel(s) to generate digital pulses defined by the number of timebase ticks that the pulse is at a high state and the number of timebase ticks that the pulse is at a low state and also adds the channel to the task you specify with taskHandle. The pulses appear on the default output terminal of the counter unless you select a different output terminal.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
counter const char [] The name of the counter to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
sourceTerminal const char [] The terminal to which you connect an external timebase. You also can specify a source terminal by using a terminal name.
idleState int32 The resting state of the output terminal.
Value Description
DAQmx_Val_High High state.
DAQmx_Val_Low Low state.
initialDelay int32 The number of timebase ticks to wait before generating the first pulse.
lowTicks int32 The number of timebase ticks that the pulse is low.
highTicks int32 The number of timebase ticks that the pulse is high.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

DAQmxCreateCOPulseChanTime

int32 DAQmxCreateCOPulseChanTime (TaskHandle taskHandle, const char counter[], const char nameToAssignToChannel[], int32 units, int32 idleState, float64 initialDelay, float64 lowTime, float64 highTime);

Purpose

Creates channel(s) to generate digital pulses defined by the amount of time the pulse is at a high state and the amount of time the pulse is at a low state and adds the channel to the task you specify with taskHandle. The pulses appear on the default output terminal of the counter unless you select a different output terminal.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
counter const char [] The name of the counter to use to create virtual channels. You can specify a list or range of physical channels.
nameToAssignToChannel const char [] The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions.
If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
units int32 The units in which to define pulse high and low time.
Value Description
DAQmx_Val_Seconds Seconds
idleState int32 The resting state of the output terminal.
Value Description
DAQmx_Val_High High state.
DAQmx_Val_Low Low state.
initialDelay float64 The amount of time in seconds to wait before generating the first pulse.
lowTime float64 The amount of time the pulse is low, in seconds.
highTime float64 The amount of time the pulse is high, in seconds.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.

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