Positional argument error in RemoteSlaveContext for modbus client read functions

[hoesentoet]

When using the RemoteSlaveContext and trying to read any modbus register, a TypeError occures:

File ".venv\Lib\site-packages\pymodbus\datastore\remote.py", line 82, in <lambda>
    "h": lambda a, c: self._client.read_holding_registers(
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: ModbusClientMixin.read_holding_registers() takes 2 positional arguments but 3 were given

pymodbus version: 3.8.3

Example to reproduce error

This is a minimal code example to reproduce this error:

import asyncio
import logging

from pymodbus.client import ModbusSerialClient
from pymodbus.datastore import ModbusServerContext
from pymodbus.datastore.remote import RemoteSlaveContext
from pymodbus.server import StartAsyncTcpServer

logging.basicConfig()
_logger = logging.getLogger()
_logger.setLevel(logging.DEBUG)


async def run_forwarder():
    """Run forwarder setup."""
    rtu_port = "COM4"
    tcp_port = "5020"

    txt = f"### start forwarder, listen {tcp_port}, connect to {rtu_port}"
    _logger.info(txt)

    client = ModbusSerialClient(
        port=rtu_port,
        baudrate=38400,
        timeout=1,
        stopbits=2,
        bytesize=8,
        parity='N'
    )
    client.connect()
    assert client.connected

    store = RemoteSlaveContext(client)
    context = ModbusServerContext(slaves=store, single=True)

    await StartAsyncTcpServer(context=context, address=("localhost", tcp_port))
    # loop forever


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

Possible fix

This error can be fixed by simply adding count= in the lambda function of RemoteSlaveContext.__build_mapping():

(pymodbus/datastore/remote.py, line 75)

self.__get_callbacks = {
    "d": lambda a, c: self._client.read_discrete_inputs(
        a, count=c, **params
    ),
    "c": lambda a, c: self._client.read_coils(
        a, count=c, **params
    ),
    "h": lambda a, c: self._client.read_holding_registers(
        a, count=c, **params
    ),
    "i": lambda a, c: self._client.read_input_registers(
        a, count=c, **params
    ),
}