[C320-list] Sending NEMA 0183 Data from Garmin Charplotter to Raymarine Autopilot

[jtamucci at comcast.net]

   I just purchased a Garmin 74DV and have been working for two weeks at
   getting the chartplotter to send position data to my Raymarine ST-5
   autopilot so I can use the TRACK feature on the autopilot.  I read
   numerous tech articles on line, and even talked to the Raymarine tech
   dept. but could not get the interface to work.  I finally succeeded in
   getting the necessary position data to the autopilot and it now the
   track function works.  I thought I'd share what I learned on this site.
   1) Contrary to what I read on many sites, you don't need an expensive
   multiplexer that interfaces with Raymarine seatalk.  Most Raymarine
   autopilots have a NEMA 0183 port. They only read NEMA standard
   configuration at 4800 baud though, not HS at 38,400.
   2) All GARMIN chartplotters use the common ground (black wire) as
   return, so the Raymarine Ve- wire must connect to the common wire of
   the GARMIN.
   3). Although the ST-5 control head has a NEMA input, it cannot be used
   to input position data.  You must use the NEMA port on the Raymarine
   computer.  I assumed the control head NEMA 0183 input port would work,
   and the Raymarine tech agreed with me.  NO!  You must go straight to
   the computer.
   So if you have aGARMIN chartplotter, and Raymarine  autopilot and on
   your boat and are having problems with them talking, I hope the above
   helps.
   Joe Tamucci
   Andante (hull 619)
   Sent from Xfinity Connect Mobile App