Voetglin driver: modbus serial kwargs have no effect

[albertogomcas]

I have not checked everywhere, but definitely this is the case in the voetglin driver, you can change for example BAUDRATE in DEFAULT_COM_KWARGS to no effect (the serial is open with 19200).

The same when using the serial_com_kwargs of RedFlowMeter.init

Both of these approaches write whatever value (i.e. BAUDRATE=value) on the minimalmodbus module, which is not used at all by minimalmodbus itself.

The only way to ensure that the parameters are used is to set them after instantiation with flow_meter.instrument.serial.parameter=value, I have no issues with that, but the dict with defaults and the argument on init are very misleading and had me chasing ghosts for a couple hours.