ModbusTCP _in_waiting not defined.

[janiversen]

Versions

• Python: 3.8
• OS: hastío
• Pymodbus: 2.51
• Modbus Hardware (if used):

Pymodbus Specific

• Client: tcp - sync

Description

The modbus integration in home assistant uses pymodbus, and lately we have started getting more and more issues with

File "/usr/src/homeassistant/homeassistant/components/modbus/modbus.py", line 305, in _pymodbus_call
result = self._pb_call[use_call][ENTRY_FUNC](address, value, **kwargs)
File "/usr/local/lib/python3.9/site-packages/pymodbus/client/common.py", line 103, in write_registers
return self.execute(request)
File "/usr/local/lib/python3.9/site-packages/pymodbus/client/sync.py", line 109, in execute
return self.transaction.execute(request)
File "/usr/local/lib/python3.9/site-packages/pymodbus/transaction.py", line 194, in execute
response, last_exception = self._retry_transaction(retries, "empty", request, expected_response_length, full=full)
File "/usr/local/lib/python3.9/site-packages/pymodbus/transaction.py", line 250, in _retry_transaction
in_waiting = self.client._in_waiting()
AttributeError: 'ModbusTcpClient' object has no attribute '_in_waiting'

We use slave 0 as default, and some users inform that the error goes away if they specify a slave > 0, but this is not consistent.

I am the maintainer of the modbus integration.

Code and Logs

 # code and logs here.
https://github.com/home-assistant/core/tree/dev/homeassistant/components/modbus

[dhoomakethu]

Is the issue also seen with 2.5.2?

[dhoomakethu]

Never mind this is a bug.

[janiversen]

Yup but difficult to reproduce and isolate, I have tried for a while….but of course you know the code a lot better.

Looking forward to see a fix.

[dhoomakethu]

Please give a try with 2.5.3rc1 .
PyPi: https://pypi.org/project/pymodbus/2.5.3rc1/

[janiversen]

will do

[janiversen]

As far as I can tell it solves the issue, however I can only do limited testing. I have issued a PR to have 2.5.3rc1 on our dev, allowing much more users to test.

[Hvitnov]

After update to 2.5.1 I have seen this issue pretty consistently on several dataloggers communicating on modbusTCP via Narrowband IOT.

Updating to 2.5.3rc1 solved this for me.