Garmin -> Garmin comms help

[whipper_snapper]

I have a Garmin 441s plotter/sounder that sends NMEA 0183 to a Raymarine autopilot. All works well, the autopilot sees the waypoint data from the plotter. Its output is set to "NMEA standard".

I also have an old Garmin GPS152, that I want to receive the same NMEA stream from the plotter - I want it to repeat the depth data.

For reasons I don't understand this does not seem to work. If I simply put the NMEA-in wire of the GPS152 into the NMEA-in plug of the autopilot, where the NMEA-out from the plotter goes in, I would expect it to work. All share a common ground. So I would just be driving 2 'listeners' from one talker which does not seem extreme.

I am wondering if it is a communication protocol issue. The plotter does not say anything about its output except that it is NMEA 0183. The GPS152 is also set to NMEA but with a baud rate of 4800 specified. There seems no way to change the baud rate.

I am also wondering if an NMEA multiplexer might overcome these problems, are they smart enough to cope with various input/output protocols?


Any bright ideas ?

Thanks

 

[pvb]

If the autopilot is getting data, the plotter must be outputting NMEA properly. Have you checked the plotter's Comms settings to see whether the depth sentences are enabled?

 

[webcraft]

.
The default protocol on the 152 is Garmin - Garmin. You have to specifically set it for NMEA-NMEA,

- W

 

[pvb]

The default protocol on the 152 is Garmin - Garmin. You have to specifically set it for NMEA-NMEA,

The OP said "The GPS152 is also set to NMEA..."

 

[whipper_snapper]

If the autopilot is getting data, the plotter must be outputting NMEA properly. Have you checked the plotter's Comms settings to see whether the depth sentences are enabled?

That is a good point, I did see while poking around that not all sentences are enabled. That is the 1st thing to try. Trouble is the boat is a 10hour drive away!

Also, I am now looking at the manual (OK, OK, I know) and I see that the plotter has a second serial comm, so I could try setting that to Garmin and using it to talk to the 152 with that also set to Garmin.