NMEA Converter crashing with Raymarine data?

[ratsea]

I have been trying to use the NMEA Converter as my Raymarine wind data in MVW is in knots but has the K identifier so is roughly halved for display on the dashboard.
It all looked good in theory using the Converter Plugin but it just crashes v4.8.6. I have checked this on two Win10 pcs.
You can installing, enable it, set a conversion, but then it hangs on closing. It forces O to reopen, then the plugin is disabled and won't enable.
Any help on this. I can bodge it by setting the dashboard wind units to Km/hr. The numbers are then right but not the description.

[ratsea]

It can be made to work by using the timed inputs in the converter plugin but it creates a virtual port which the dashboard still isn't picking up

[rooiedirk]

What is the conversion format string you using? And please an example of the nmea input sentence.

[ratsea]

I am trying to replace the 'K' in this sentence:
$IIMWV,336,R,005.6,K,A*23
with an 'N' as the data is in knots, but the raymarine output must use a K for Knots as the data is in Knots.
The Plugin formula is very simple:
$IIMWV,$IIMWV1,$IIMWV2,$IIMWV3,N,A
and you can see the actual data being received in Blue above the edit box.
If you send every 1 or 2 seconds it does output data but does not replace the original NMEA stream, it just creates a virtual port output that the dashboard ignores but can be seen in the NMEA debug window.
like this:
$IIMTW,024.4,C*21
$IIMWV,023,R,010.4,K,A*22 Input line
$IIVHW,,T,359,M,00.00,N,00.00,K*6A
$IIMWV,23,R,10.4,N,A*27 Converted
Leading zeros are missing, but that shouldn't matter should it

I am on Windows 10.
If you change the edit to 'send after update all variables', it just freezes.
Thanks

[rooiedirk]

Ah, What you are doing is sending a $IIMTW.... line using data from a $IIMTW line.
But the newly constructed sentence is send everywhere in OpenCPN including the nmeaconverterPI. So the PI is receiving its own sentence (without knowledge from where it comes) and constructs a newone from it and sends it again. And so on. You are making a perfect infinite loop, no wonder OpenCPN is crashing


By making it a timed tranmission, you will send only every 'x' seconds, so there is no infinite loop. You should however make the transmission interval lower than the original sentence, to make sure that the data you are using is from the instrument and not from the PI.
But then still the Dashboard is receiving both sentences, the original and the one from the PI. As a result your dashboardinstrument will start flashing between a 'K' anf a 'N '.

[ratsea]

Thanks, that explains it. I have now added the 5th term as $IIMWV5 for the A and set the timer to 1 sec and that for some reason eliminates the dual N and K display and all is working fine.
This will be a very useful PI
Thsnks

[rooiedirk]

Just think about it, what also could work is using wildcards. It looks like raymarine is using fixed number length and prefix it with zero's if needed.

Then something like:
$IIMWV,$IIMWV?????????????K1,$IIMWV?????????????K2,.......
Should do the trick as well. (Make sure you have exact the right number of '?'.

[rgleason]

Doesn't the raymarine instrument have settings to change the parameter? Nevertheless, good excercise here.

[ratsea]

I would have expected Raymarine to have a setting too, and it is set to Knots for all speed items, but the ST60 Multi outputs the NMEA sentence with a K and the O Dashboard thinks that is Km/HR. If you set it to Km, the numbers are right.
As you say an interesting bit of learning on the Converter.

[rgleason]

Ratsea, thank you. Which Raymarine instruments?

[ratsea]

I am using the NMEA output from the ST60 Multi as the input to OpenCPN for the wind/speed/depth data. I have ST60 Wind, Depth, Speed and Multi (not the Graphic). They are all set to Knots. I changed the wind units on the ST60Wind to M/S - it was the only other option. This had no effect on the NMEA sentence unit identifier. It was still K.

I also tried resetting the Multi but that is set by the master, ie Wind sets the wind units.

Without any adjustment, the O Dashboard displays about half the value shown on the ST's with its units set as Kts, but if you change them to Km/hr the data is corrected albeit that unit description is wrong. I note that the K identifier is the 'offical' one for Km/hr, so I suspect Raymarine have got it wrong. They don't offer Km/hr as a units option one these units.
I am somewhat surprised no one else has had this before, and it's only wind the speed is fine.

Hope this helps,
Richard

[rgleason]

ST60 Wind, Depth, Speed and Multi (not the Graphic). They are all set to Knots.

Very interesting, I have the same instruments. What device do you use to convert to nmea0183? For opencpn I use gadgetpoole.de Tiny Seatalk Converter. I'll have to note what is happening.

[ratsea]

Originally Posted by rgleason

What device do you use to convert to nmea0183?

I thought I had said. I use the NMEA output functionality of the ST60Multi.


It has NMEA input and output. The input is the GPS stream, and the output the Depth/Speed/Wind data.


Richard

[rgleason]

Yes, you did say so. Sorry, I don't have an ST60 Multi, so didn't realize that Nme0183 is available on that. I have ST60 Tridata and ST60 Wind.

[ratsea]

Interesting that you don't have the same issue. It must be the Multi not doing the conversion properly.
The NMEA converter solves the problem though. The manual could do with a few more examples and the explaination I was given about O freezing.