At HA (Core2026.5.4 OS17.3) pymodbus V13.11.2 Problem at read_holding_registers with device/slave param

[Herby62]

Hi, I'm new with HA and pyscript, and need help with param fof client_device_number. Is there a decoding problem??

It doesn't matter what param (slave, slave_id, dev_id device_id) is used at read_holding_registers I got parsing errors:
(import pymodbus, from pymodbus.client import ModbusSerialClient)

dev_id:
File "/config/custom_components/pyscript/global_ctx.py", line 379, in load_file await ast_ctx.eval() File "/config/pyscript/test_modbus1.py", line 69, in file.test_modbus1 result = client.read_holding_registers(address=REGISTER_START, count=2, dev_id=SLAVE_ID) TypeError: ModbusClientMixin.read_holding_registers() got an unexpected keyword argument 'dev_id'. Did you mean 'device_id'?

device_id:
File "/config/custom_components/pyscript/global_ctx.py", line 379, in load_file await ast_ctx.eval() File "/config/pyscript/test_modbus1.py", line 69, in file.test_modbus1 result = client.read_holding_registers(address=REGISTER_START, count=2, device_id=SLAVE_ID) File "/usr/local/lib/python3.14/site-packages/pymodbus/client/mixin.py", line 113, in read_holding_registers return self.execute(no_response_expected, pdu_reg.ReadHoldingRegistersRequest(address=address, count=count, dev_id=device_id)) ~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/usr/local/lib/python3.14/site-packages/pymodbus/client/base.py", line 202, in execute return self.transaction.sync_execute(no_response_expected, request) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/usr/local/lib/python3.14/site-packages/pymodbus/transaction/transaction.py", line 132, in sync_execute response = self.sync_get_response(request.dev_id, request.transaction_id) File "/usr/local/lib/python3.14/site-packages/pymodbus/transaction/transaction.py", line 86, in sync_get_response if not (data := self.sync_client.recv(None)): ~~~~~~~~~~~~~~~~~~~~~^^^^^^ File "/usr/local/lib/python3.14/site-packages/pymodbus/client/serial.py", line 302, in recv size = self._wait_for_data() File "/usr/local/lib/python3.14/site-packages/pymodbus/client/serial.py", line

slave:
File "/config/custom_components/pyscript/global_ctx.py", line 379, in load_file await ast_ctx.eval() File "/config/pyscript/test_modbus1.py", line 69, in file.test_modbus1 result = client.read_holding_registers(address=REGISTER_START, count=2, slave=SLAVE_ID) TypeError: ModbusClientMixin.read_holding_registers() got an unexpected keyword argument 'slave'

Thank you for your help,
best regards, Herbert

[janiversen]

First of all you should upgrade to the newest pymodbus, 3.11.2 have a number of known problems.

You ask about client_device_number but that does not exist in pymodbus. And just to be clear you do NOT get passing errors in all your examples.

"dev_id" do not exist as parameter, neither does "slave", please read the documentation or at the very least check the call signature.

It seems your call does a timeout without an answer from the device, but without a proper debug file and sample code, I really cannot help you, probably you do not have try/except in your code.

[Herby62]

Jan, thank you for your input.
But that happens at homeassistant after saving the .py file (codechecking) and I can't run the code.
It seems that happened at pyscript/global_cty.py. if I use serv_id the message told to use service_id and if i user service_id it suggest for serv_id. I'll try to do update for 13.0

[janiversen]

This is the pymodbus project not the homeassistant project!

Your question do not really have anything to do with pymodbus.

[janiversen]

You could also consider using the modbus integration, that might prove a lot easier in your situation.