NMEA0183 connecting various devices

Tammany

Tammany

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New to NMEA and was wondering if this connection diagram looks OK. My chartplotter is a garmin 50s which has 2 inputs/outputs, wind speed is the nasa one with nmea018 out and autopilot simrad TP22. I also intend on fitting a AIS transceiver at a later date. I know you can receive 1 but transmit on 3 except AIS which needs a dedicated port so does this look correct?

Input 1 - wind
Output 1 - tillerpilot

Input 2 - AIS
Output 2 - not used
 
Tammany said:
New to NMEA and was wondering if this connection diagram looks OK. My chartplotter is a garmin 50s which has 2 inputs/outputs, wind speed is the nasa one with nmea018 out and autopilot simrad TP22. I also intend on fitting a AIS transceiver at a later date. I know you can receive 1 but transmit on 3 except AIS which needs a dedicated port so does this look correct?

Input 1 - wind
Output 1 - tillerpilot

Input 2 - AIS
Output 2 - not used
Click to expand...

The 2nd NMEA 0183 channel runs at 38.4 KBaud for AIS incoming data . It would seem likely the 2nd output also runs at that speed. Provided whatever AIS transceiver you buy can generate / accept the 2nd channel, you will be in business. As it is most likely the transceiver will be looking for GPS position data for an input - it just MIGHT want that at 4800baud - the slower NMEA 0183 speed?? You might be able to reconfigure what is sent?
There is also an NMEA2K connection on the 50s - which is far simpler to configure and wire up - if your proposed transceiver can do NMEA2K - forget messing with the old network?
 
What kit do you have? Most manuals can be found on-line. NMEA0183 is quite a loose standard and there are cases where there are several standard messages for the same thing, with some being used for the latest generation and others used by older kit, so don't make assumptions about what data can be successful passed - check the manual to confirm for each combination. There are also a few non-standard variants (e.g. Stowe) but I'm guessing that isn't applicible.

Reading between the lines, I'm guessing your radio provides the AIS data (and has its own built-in GPS as you say). Or do you have nothing at the moment?

If the latter case then it's just a matter of feeding the wind instrument output into the chartplotter and feeding the autopilot sentences out of that. Wind is one area to check what sentences are used to make sure both sides read the same type of sentences (or have enough of them in common).

Does the chartplotter echo wind data? Does your autopilot accept it? Maybe you also need to look at feeding wind data direct to the autopilot separately.
 
No ais at the moment. Looking to fit a matsutec one in the future. Radio is a dsc gps set so going to leave that as stand alone.
 
I can change the baud to 38400 ok. Just want to be able to see other ais boats on the plotter. Its compatible for ais. Sounds like I'm good to go then.
 
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