Jump to content

NMEA 2000 PGNs

Recommended Posts

I'm having a set-to with Simrad.  I'm trying to automate the process of making a DSC call to a selected AIS target on my plotter.  Simrad plotter, Simrad VHF, AIS from a Vesper XB-6000.

Simrad "help"desk has been less than useful.  They don't understand what their own gear is advertised as doing and can't answer simple questions.  If you can understand what has been typed.  

They say that Vesper isn't compatible, although it is NMEA certified and provides all the relevant data to the NSS9 Evo3 plotter.  Vesper support have been excellent and agreed with my layman's guess that the plotter should be generating the PGN for the DSC call, as it is the device which knows which target I'm trying to call.  Simrad says the AIS should be transmitting the PGN.

Simrad HD advised I was missing PGN#12908.  That doesn't exist.  They said refer to the manual, which specifies PGN#129808.  That doesn't exist either.  I suggested tit was supposed to be PGN#12808 - DSC Call Information.

My question is - does anyone know how this stuff works?  I'm guessing the only answer is a software fix on the plotter to output the correct PGN but I can't get any sense out of the freakin' edjit at Simrad.  Telling him he was talking crap probably didn't help either....

Link to post
Share on other sites

Well, the issue is that there is currently no standard for this function. Navico and the other manufacturers will use the non Navico device as an excuse not to help.

Several manufacturers (incl Simrad) can do it using proprietary sentences with their own gear, but  NMEA 2000 is a closed standard, and to be a member with approved gear the manufacturers have to sign a non disclosure contract. None of them will tell you how to do this.

So, your best bet is likely signal K (Open source standard) or Kees - https://yachtelectronics.blogspot.com/ kees@keversoft.com. He may know. Again, he may not tell you.

The easiest way at this point is to stick with one manufacturer - so change your AIS. I know that is a shame, as the Vesper is a great unit. 

The only real way to do this would be to get a Simrad system that does work, and record the sentences generated, then reverse engineer.  Which is a breach or your user agreement for the Simrad MFD.

I do agree that the MFD should be (and does on all the navico systems, incl Simrad) generating the PGN to make the radio call. 

Link to post
Share on other sites

Oh, and PGN 129808 is for an INCOMING DSC call, and is what allows the plotter to show that - like a distress signal etc in the correct location. There is as yet no defined PGN for outgoing, as mentioned above. Simrad use a proprietary one, PGN 130816.

See also https://mt.panbo.com/2015/04/direct-dsc-vhf-calls-to-ais-targets-a-nmea-2000-standard.html


Link to post
Share on other sites

Yeah, thanks IT!  I am staggered to find the official NMEA PGN list is incorrect and has been for 10 years now!

That Panbo link is awesome - relieving to see others have gone down exactly the same rabbit hole and had similar conversations with Navico support.  Sad to see that the post was 5 years ago and the same problem still exists.

I'm pretty confident I'm on V20.1, although I'm doing a road trip in the South Island at present so not 100%.  Will check.

The VHF is an RS20, as recommended to me by Bay Marine Electronics.  I spelt out what I was trying to achieve and even quoted the Simrad manual about compatible DSC radios.  They aren't replying to my emails.

Happy to listen to any recommendations.  I'm reluctant to spend yet more money on electronics, I have had a bad run with buying sh*t that either doesn't work or doesn't do what is advertised.  

Link to post
Share on other sites

OK, A couple of basic questions first. Sorry if this is too basic, but have you programmed your MMSI into the RS20? DSC wont work without it. Have you tried a manual DSC call and made certain that that is working. What software version is on the RS20? - it displays that briefly on startup.

I had a play with a B&G setup today, worked fine. It was a B&G Vulcan MFD, and a  B&G RS60B radio (Built in AIS transponder). The call button is present on the bottom of the AIS info list for any AIS target on the MFD.  Press that and it says "do you want to make a call to MSIXXXXXX on ch70" Press yes, and away it goes. 

As far as I can tell, only the MFD and the radio are involved in the call, but I'd have to record the N2K data to be certain. So it SHOULD work on a Simrad MFD and Radio with current software if properly configured. 

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...