NMEA signal from Raymarine S3G to DSC VHF

[DickB]

I cannot get a GPS position value to my Standard Horizon VHF from my S3G autopilot. The chart plotter nmea output works fine, but it already being used for the AIS. Any inspiration? The autopilot is outputting a signal (LED test works fine). I am not quite sure what to do now!!!

 

[Ex-SolentBoy]

Have you read this?

Must be port 2

 

[John100156]

I used a Raymarine NMEA bridge it also links a PC and Seatalk devices - fitted my SH GX2100E VHF a couple of months ago and it all worked fine.

 

[Bru]

Why not simply connect the chart plotter output to the VHF a well as the AIS?

As discussed in other recent threads the NMEA output from the chart plotter should be able to drive at least 4 receiving devices

 

[DickB]

Why not simply connect the chart plotter output to the VHF a well as the AIS?

As discussed in other recent threads the NMEA output from the chart plotter should be able to drive at least 4 receiving devices

Problem is that AIS is 38400 baud, and the VHF is 4800! Otherwise I could you use the same port.

Thanks anyway

 

[DickB]

Why not simply connect the chart plotter output to the VHF a well as the AIS?

As discussed in other recent threads the NMEA output from the chart plotter should be able to drive at least 4 receiving devices

Have you read this?

Must be port 2

Yes, it should transmit correctly, but for some reason nothing comes through. Raymarine told me that it does transmit NMEA. Beats me...

 

[DickB]

I used a Raymarine NMEA bridge it also links a PC and Seatalk devices - fitted my SH GX2100E VHF a couple of months ago and it all worked fine.

This looks a possibility. I'll check it out! Thanks

 

[nimbusgb]

I have just installed a similar device on a boat in Brighton marina. I used an Arduino board and a line driver. It strips the GPRMA/B/C sentence out of the AIS NMEA stream going in to the MFD, drops it to 4800 baud and feeds it to the radio.

Cost about £20 vs the £125 for a Raymarine bridge. Arduino code and a circuit diagram of the driver by PM if you want.

 

[Bru]

Problem is that AIS is 38400 baud, and the VHF is 4800! Otherwise I could you use the same port.

Thanks anyway

Ah! Didn't think of that

Oh well

 

[Baggywrinkle]

EDIT: Sorry, I thought you wanted it all out of the plotter, not the Autopilot. Ignore my waffle, but I'm going to leave the post because it might be useful to someone, but I'm pretty sure these values are calculated by the plotter and will only be re-transmitted by the autopilot if it receives them from the plotter.

The Raymarine gear as far as I can tell accepts NMEA in but does not transmit on MNEA. All NMEA sentences are then relayed on Seatalk but if you want seatalk data on NMEA then a converter is needed.

To get NMEA data out of a Standard Horizon plotter (I've got the Standard Horizon CP300) then connect the NMEA Common of the Plotter (Green Wire) to the Raymarine NMEA -ve of the Autopilot and the Brown wire from the Plotter (Port 1 Out) to the NMEA +ve of the Autopilot. (I've got a Raymarine ST4000+) This is the same wire that sends GPS data to the DSC VHF (In my case a GX2100E). The port should have no problem driving 2 listeners.

Then go into the advanced settings in the Plotter and ensure that all the relevent NMEA sentences that you want for the Autopilot are enabled on Port 1.

If you have no fishfinder then Port 2 is usually used for AIS input on CP180/300. (The CP300 has more i/o ports than the CP180 so is a little more flexible).

Finally, enabling a port for AIS input on a Standard Horizon CP180/300plotter disables any output from that port as nothing is sent from the plotter at 38400 Baud. It only recieves. Port 2 In on my CP300 is connected to the SH GX2100E AIS ouput so Port 2 Out on the Plotter is not connected to anything.

I have a wiring diagram which I can send if you want. Just PM me.

 

[AngusMcDoon]

Maybe your VHF is expecting lat/long in the RMC sentence, but is only getting GLL. Not much you can do about it if that is the case. As I always say on these GPS to VHF problems, buy a BR-355 for £25 and problem solved.

 

[pvb]

Maybe your VHF is expecting lat/long in the RMC sentence, but is only getting GLL. Not much you can do about it if that is the case. As I always say on these GPS to VHF problems, buy a BR-355 for £25 and problem solved.

Standard Horizon radios do accept GLL, although they say RMC is recommended.

 

[John100156]

The Raymarine NMEA Bridge works perfectly coupling my SG3 and new SH VHF, it was already fitted on my boat when I fitted the radio, which is why I used it, interested in other solutions though.