The AF-Pilot needs ARINC (GPSS and GPSV) signals if it will be driven by a NAV or EFIS source. The AF-Pilot also has the ability to follow a GPS heading fed from a GPS device. This can be fed by the EFIS or a standalone device.

Pin 17 should be fed by the a 1200, 2400, 4800 or 9600 baud signal of NMEA-0183, Garmin Aviation Format, Apollo/UPSAT MovingMapor GPSS format. This provides directional reference to the autopilot.