[CA] [CA11] Interfacing SmartPilot S3G course computer to Garmin gpsmap 4208

[GALLENHARMON]

I'm wondering if its feasible to interface my Raymarine S3G Smartpilot with my Garmin 4208 chartplotter with the goal of being able to have the autopilot "track" command function via a course plotted on the chartplotter.
I have upgraded the original controller with a new p70Rs and the autopilot and other Raymarine equipment on the Seatalk 1 network are ST60 depth sounder and ST60 paddlewheel knotmeter. I have removed an old Raymarine hsb2 PLUS Series color LCD radar display on which the screen had deteriorated so badly it was unusable.
The Garmin 4208 is connected to a radar antenna and gps 17x antenna via NMEA 2000 backbone. Garmin has input connections for NMEA 2k cable, NMEA 0183 cable, garmin network cables, video cable and power cable.
I know this is a scant amount of information and at this point would like to know if you feel such an interface is possible.
Thank you,
George Harmon

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum George,

Were this not involving a legacy Raymarine autopilot and a third party NMEA 2000 system, I might have suggested that a SeaTalk to SeaTalkng Converter Kit be used as part of the solution. However, the time proven solution would be to simply:
- interface the 4800 BAUD NMEA 0183 output port of the third party chartplotter/MFD to the NMEA 0183 input port of either the autopilot's control head or course computer.

If additionally desiring to have the heading and/or rudder angle data supplied to the third party chartplotter/MFD:
- interface the 4800 BAUD NMEA 0183 input port of the third party chartplotter/MFD to the NMEA 0183 Port 1 OUT of the autopilot's course computer.