The Sirius SCH2P RS232 protocol is two way. My SCH2P Is connected to my AVP. When I command the AVP (over RS232) to connect to the Sirius Radio input port, it turns on the Sirius Radio using a 12 volt trigger. From that point forward I can completely control the Sirius radio with full feedback as to status and what is playing. This is done over RS232 coming from a PC that controls the Theater or from an iPad that controls all my home Automation. The iPad talks to the PC controlling the theater over TCP which is controlling the Sirius SCH2P.