hi @dietlman,
I think what you are looking for is the general modbus configuration to create the reference object for the modbus call (which I seemed to have missed to include in my original description).
For me, this looks like this (to put in configuration.yaml):
modbus:
- type: tcp
host: 192.168.x.x
port: 502
name: fronius1
The device ID (in my case: 1 for the inverter and 200 for the smart meter you will place in the specific call).
Hope this helps.