You do know that with the RP-6 you can do RS232 to the S12. I control all my S12's with RS232. If thats not an option I would use a receiver per keypad port and just have the room report to the receiver that is linked to that zone. But with the RP-6 you can do 6 ports or RS232. So 1 port RS232 to the S12 and you have 5 left over for IR or RS232 to your sources. The codes for the S12 are in the owners Manual and are easy enough to understand.

As for the guy that used the matrix instead of the S12 it must be nice to waist money(not meant as an insult). If your S12 is programed right you wouldnt need to do any compliated switching. Remember this system is not like the Z-Series Elan. You can actualy tell it how to switch and what video goes to what source. So you select the source and the video will follow.