How should I intsall the 2nd meter for X3-Hybrid system? or can I use for the 2nd one the CT?

The 2nd measurement device of X3-Hybrid G4 system must be meter.The two meters share the same PIN connection, both use No. 4 and 5 of the meter/CT port. You can use a RJ45 coupler to connect the two meters' communication cable.