Modbus and Software Serial Libraries

Could anybody advise me please on, "ModbusRTUClient.begin(baudrate, config);" to direct communications to a particular serial port?

I am wishing to to use Modbus protocol over a Software Serial Uart on the Nano for several boards to communicate with each other.

I'm unsure how to specify a Modbus serial channel.

If anybody could help I'd be most grateful, and if I'm missing something obvious, apologies.

I can't seem to find the connection between specifying the Modbus Client and the serial port to use for communication,

Kind Regards, Robin

robinbro:
I am wishing to to use Modbus protocol over a Software Serial Uart on the Nano for several boards to communicate with each other.

This may be impossible or impractical.

robinbro:
I am wishing to to use Modbus protocol over a Software Serial Uart on the Nano for several boards to communicate with each other.

Modbus (Modbus RTU) is single Master. So your requirement "communicate with each other" will not be working, better ... will need lot of workarounds to make it working.

rethink your communication structure or choose another communication protocoll.