NMEA problems between Garmin GPS 152 & Autohelm ST4000

[curious1]

Has anyone overcome the following problem which has suddenly appeared.
My Autohelm ST4000 will not set up correctly when attempting to navigate to NMEA information from my Garmin 152 'Navigate to' function.
The Autohelm only shows 2 of the 3 required fields, ie. bearing, and 000's in the distance to object field.
The display does not show the "turning to port or starboard" field.
An NMEA signal is being produced by the GPS as it is giving a position to the DSC/VHF radio.
Is the problem with the GPS or the Autohelm?
Absence of Cross track error data comes to mind but I have no way of proving it.

 

[Danny]

Re: NMEA problems betwen Garmin GPS 152 & Autohelm ST4000

The Garmin 152 sends GPXTE and GPRMB sentences as standard and the ST4000 should be able to get the XTE from either of these.

It sounds like the Garmin is acting as though it hasn't been told to GOTO anywhere! If you've definitely set up to go to a waypoint or follow a route then I would guess that the fault is in the Garmin.

The only way to check for certain would be to use a PC or a protocol analyser to check that the RMB and/or XTE sentences are being transmitted.

 

[jackho]

Disconnect your DSC/VHF to see if it solves the problem. I had a similar problem losing data to my chart plotter.