The Energy Meter can be used for four things:
To connect multiple Energy Meters, wire each meter to a separate RS485-USB converter. Which are then each plugged into a separate USB socket on the GX device. See NOTE 1 Below
Connecting multiple ET112 meters to the same RS485-USB cable is not possible: the ET112 meter has no display and its Modbus address can therefor not be changed.
Note 1 You can connect the ET112 in parallel, just need to change the MOD address to another number using the Configuration software from the supplier which is free from Carlo Gavazzi Web site.