I just got off the phone with Epson. They too are have difficulty finding documentation on what the 2 ports A and B are on the back of the video processor.
Like BrentM they first thought I was talking about the projector itself and they told me these were 12v out to drop screen but latter they called me and told me that these are actually 12 v trigger port ins. But they added even though my avr has 12 volt trigger out, it will not trigger the processor on because "it is not CEC". That's where this became unclear to me. They were surprised themselves the answer was not on their own documentation. So even thought my AVR is trigger out and processor is trigger in...it won't work because it's not CEC. Figure it out!?