Have you looked at the Modbus docs? Example setups at the bottom
Examples for similar meter
The bit you seem to have missed.
Serial Bridge thing represents your device (meter)
Poller thing reprsents a block of Modbus registers.
You may have many pollers on one device - e.g. different address ranges, different register types.
Data thing represents how to interpret one or two registers from that block. e.g. a 32-bit integer.
Each poller thing may have, usually does have, many data things.
