feat: supply string type

[hongda3141]

PR Checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

If your build fails due to your commit message not passing the build checks, please review the guidelines here: https://github.com/edgexfoundry/device-modbus-go/blob/master/.github/Contributing.md

What is the current behavior?

Issue Number:

What is the new behavior?

Does this PR introduce a breaking change?

• Yes
• No

New Imports

• Yes
• No

Specific Instructions

Other information

[hongda3141]

change log:

1. modify variable "stringLength" to "wordLength"
2. change bit length of string from 1 to 16
3. change swith-case to if-else block

[hongda3141]

@weichou1229
PTAL again ，thanks

[cloudxxx8]

We changed the DeviceProfile data model.
Please modify the sample profile. Here is the example:
https://github.com/edgexfoundry/device-modbus-go/blob/b09d9ba1a72cafb6b38617a4d5eb8b9f0ac4b1bc/cmd/res/profiles/modbus.test.device.profile.yml

[hongda3141]

@weichou1229
PTAL again ，thanks a lot for the advice

[weichou1229]

No problem.
Since we change the data model in V2, please verify the GET and PUT command works with edgex-go master branch.

[codecov-commenter]

Codecov Report

Merging #262 (98f7e93) into main (5a20fcc) will decrease coverage by 1.08%.
The diff coverage is 29.03%.

@@            Coverage Diff             @@
##             main     #262      +/-   ##
==========================================
- Coverage   42.25%   41.16%   -1.09%     
==========================================
  Files           6        6              
  Lines         542      566      +24     
==========================================
+ Hits          229      233       +4     
- Misses        275      293      +18     
- Partials       38       40       +2     

Impacted Files	Coverage Δ
internal/driver/deviceclient.go	67.97% <29.03%> (-8.00%)	⬇️

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[hongda3141]

@weichou1229
that`s right, profiles should update to v2 too,
PTAL again ，thanks

[weichou1229]

@hongda3141
The Get and Put command works incorrectly.

1. For the Get command, I thought the value should decode to a readable string.
   "value" : "\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000"

% curl http://localhost:59882/api/v2/device/name/Modbus-TCP-Read-String/StringB | json_pp
{
   "apiVersion" : "v2",
   "event" : {
      "apiVersion" : "v2",
      "deviceName" : "Modbus-TCP-Read-String",
      "id" : "669f5d9f-2004-47ad-9533-e15ff452304d",
      "origin" : 1623834796385661000,
      "profileName" : "Test.Device.Modbus.String.Profile",
      "readings" : [
         {
            "binaryValue" : null,
            "deviceName" : "Modbus-TCP-Read-String",
            "id" : "3fb25504-d6da-4525-8143-3a55f84299ad",
            "mediaType" : "",
            "origin" : 1623834796385624000,
            "profileName" : "Test.Device.Modbus.String.Profile",
            "resourceName" : "StringB",
            "value" : "\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000",
            "valueType" : "String"
         }
      ],
      "sourceName" : "StringB"
   },
   "statusCode" : 200
}

2. For the Put command, I got the transform error.

% curl http://localhost:59882/api/v2/device/name/Modbus-TCP-Read-String/StringB -X PUT -H "Content-Type: application/json" -d '{
    "StringB":"test-string"
  }' | json_pp
{
   "apiVersion" : "v2",
   "message" : "request failed, status code: 500, err: {\"apiVersion\":\"v2\",\"message\":\"error writing DeviceResourece StringB for Modbus-TCP-Read-String -\\u003e transform command value failed, err: failed to transform test-string to []byte\",\"statusCode\":500}",
   "statusCode" : 500
}

[hongda3141]

thanks very much，i`ll fix that

[hongda3141]

No problem.
Since we change the data model in V2, please verify the GET and PUT command works with edgex-go master branch.

@weichou1229 hi，i found there is no edgex-lanch.sh in branch master, could you tell me which branch did you used for edgex-go? i always used and tested in fuji, but i think maybe it is too old for v2 version.

[weichou1229]

@hongda3141

i found there is no edgex-lanch.sh in branch master

It was removed in master branch

could you tell me which branch did you used for edgex-go?

master branch

You can use the following script before community add it back.

#!/bin/bash

DIR=$PWD
CMD=../cmd

# Kill all edgex-* stuff
function cleanup {
	pkill edgex
}

# disable secret-store integration
export EDGEX_SECURITY_SECRET_STORE=false

###
# Core Command
###
cd $CMD/core-command
# Add `edgex-` prefix on start, so we can find the process family
exec -a edgex-core-command ./core-command &
cd $DIR

###
# Core Data
###
cd $CMD/core-data
exec -a edgex-core-data ./core-data &
cd $DIR

###
# Core Metadata
###
cd $CMD/core-metadata
exec -a edgex-core-metadata ./core-metadata &
cd $DIR

trap cleanup EXIT

while : ; do sleep 1 ; done

[hongda3141]

thanks a lot

[hongda3141]

@weichou1229
i fixed the PUT and GET command error,
PTAL thanks

[hongda3141]

@weichou1229
i update the codes with using build-in method for trimming the zero value,
PTAL thanks

[weichou1229]

LGTM

[cloudxxx8]

hold until 2.0.0 release
this is targeting to 2.0.1

[cloudxxx8]

LGTM