I am upgrading my MFD from E120 to C120 3rd generation. The C120 is NMEA/Seatalk/Seatalk hg/Saetalk hs compatible and I need to figure out how to connect the autopilot computer to the Seatalk hs network (I already have the hs switch). I have done most of the navigation installations since the boat was new but the autopilot was already installed. Do you know where the computer was installed? and how is connected to the head - Seatalk or other.