Could someone from tech support confirm that: 1) When pairing multiple adapters in the same room/multiplug we need to connect them with ethernet cable as well? 2) When we have more than 2 PLCs,...

Just by pluging it in will pair to the network (provided that all your PLCs are installed on the same electrical phase/for 3-phased network powered buildings). Pressing the button will enable and...

The devices must belong to the same electrical (not ip) network to implement one powerline network. This means that the plugs you are using must be connected to the same electrical "phase" or...