Hey looking at the diagram for the "CN701 12 Pin Connector", the L & R inputs should be no problem, the grounds I take it can be left alone if my input device is already grounded, and there there is the "REQ-SIG In", "Rx-SIG In" and the "Tx-SIG Out"

Well the Rx and Tx are serial input and output connections, which I assume are to control the ch changer via the headunit controls, but what is the "REQ-SIG In" for? Is it for CD changer requesting input, or in other words this tells the headunit to switch the AUX on? If so, then maybe it will work the same way as the 8 pin DIN??

Any thoughts?