Can one By-me control unit communicate with another By-me control unit?

Yes, there may be multiple BUS lines each with 1 control unit, where only the activation of the following scenarios can be shared: activating scenario n. X on a BUS line will also automatically activate scenario n. X of the other control units , as long as the scenarios in question are set as "Global Scenarios" and not, such as "Normal Scenarios" when they are created. Scenarios are the only thing that can be shared between two or more home automation systems with different control units. Pay special attention to the initial settings of various control units in the initialization phase when there is a system with more than one By-me control unit. When there is a GSM communicator in the system, it can manage up to eight control units, but in the case of a greater number of control units, there may be more GSM communicators, each dedicated to a maximum of eight.