dm-aiomodbus 0.2.1

This is my custom aiomodbus client

DM-aiomodbus

Urls

• PyPI
• GitHub

Example

Connection

• Serial

  from dm_aiomodbus import DMAioModbusSerialClient
  
  modbus_client = DMAioModbusSerialClient(
      port="/dev/ttyUSB0",
      baudrate=9600,
      bytesize=8,
      stopbits=2,
      parity="N"
  )
  

• TCP

  from dm_aiomodbus import DMAioModbusTcpClient
  
  modbus_client = DMAioModbusTcpClient(
      host="192.168.0.0",
      port=501
  )
  

• Simulator (always returns mock data)

  from dm_aiomodbus import DMAioModbusSimulatorClient
  
  modbus_client = DMAioModbusSimulatorClient()
  

Usage

• Usual client

from dm_aiomodbus import DMAioModbusTcpClient
import asyncio


async def main():
    # create client
    modbus_client = DMAioModbusTcpClient(
        host="192.168.0.0",
        port=501,
        name_tag="my_tcp_plc"
    )

    # read registers
    reg_258_259, = await modbus_client.read_holding_registers(258, count=2)
    reg_256 = await modbus_client.read_holding_registers(256)
    # read second slave-device
    reg_260_2 = await modbus_client.read_holding_registers(address=260, slave=2)
    print(reg_258_259, reg_256, reg_260_2)

    # write registers
    status_256 = await modbus_client.write_register(256, 1)
    print(status_256)
    # write second slave-device
    await modbus_client.write_register(260, value=0, slave=2)


if __name__ == "__main__":
    asyncio.run(main())

• Return-errors client

Error messages are returned with the execution result

from dm_aiomodbus import DMAioModbusTcpClient
import asyncio


async def main():
    # create client
    modbus_client = DMAioModbusTcpClient(
        host="192.168.0.0",
        port=501,
        return_errors=True
    )

    # read registers
    # get values and error (if present, else "")
    reg_258_259, err1 = await modbus_client.read_holding_registers(258, count=2)
    print(reg_258_259, err1)

    # write registers
    # get write status and error (if present, else "")
    status_256, err2 = await modbus_client.write_register(256, 1)
    print(status_256, err2)


if __name__ == "__main__":
    asyncio.run(main())

Optional init parameters

Parameter	Type	Default Value	Description
return_errors	bool	False	Error messages are returned with the execution result
execute_timeout_s	int	5	requests timeout (s)
disconnect_timeout_s	int	20	timeout waiting for an active connection after the last request (s)
after_execute_timeout_ms	int	3	timeout between requests (ms)
name_tag	str	auto	name tag for logger suffix

Set custom logger

If you want set up custom logger

from dm_aiomodbus import DMAioModbusTcpClient


# create custom logger
class MyLogger:
    def debug(self, message):
        pass

    def info(self, message):
        pass

    def warning(self, message):
        print(message)

    def error(self, message):
        print(message)


# set up custom logger for all clients
DMAioModbusTcpClient.set_logger(MyLogger())

Run in Windows

If you run async code in Windows, set correct selector

import asyncio
import sys

if sys.platform == "win32":
    asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())