The schematic of Rchv2 is available here. It's made with "Kicad" which is a nice open source for electronics, schematic and PCB.. See kicad home page to get it. Thanks to Andreas Thorn for his help and contribution on this schematic.
Some pictures of the Assan X8D module installation in a Futaba T12Z. Lock switch and led are located on the same side than antenna. PPM signal, + and - are taken from the back of the middle board which carries the trainer connector.