Which one is the bus used to interconnect a RadianT365 radiator central (AZRA6CB1RAD[W]) with other centrals?

To interconnect all the Airzone systems' control units, you must use the home automation connector of each of the control units. Remember that the connection must be made using the data bus (blue and green wires) without using the power wires. Also, bear in mind that one of the central units must have the Airzone Cloud Webserver connected to this port. In this case, use the upper connector of the Webserver for the blue and green wires.