serial nmea again

[Newt2u]

I have a problem in getting my wind data into signalK. I have set up a serial link to digital yacht's nmea/USB adaptor connected to my NASA nmea wind instrument. The adaptor seems to be working in that its debug light is flashing and the input has triggered the wind panel in the signalK instruments. However on looking at the data, I see only one wind direction and one speed message and the instrument panel does not respond to changes in wind speed and direction. Can anyone advise what may be happening to seeming stop the stream after the first sentence? Baud rate is set to 4800, which matches the wind instrument and the usb adaptor matches the application, in this case the Signal K server.

[Newt2u]

I have been trying to track down the problem described above today after reading docs on debugging. Managed to locate the following error message on the nmea0183-signalk stream.

   

It seems there is a parse error in the wind instrument sentence. The sentence is correct with the exception of what appears to be a non-printable/non-standard character that precedes the $ symbol. Data is from NASA nmea wind instrument input to RPi3 using a digital yacht nmea to USB adaptor. Baud rate is correct (4800) and both adaptor and log show I am getting regular data that is correct apart from this spurious leading character (i.e. Wind instrument, MWV sentence, relative wind, 115degrees, speed 0, knots, data valid. As I said above I did get one correct sentence on setting up the input initially but not since.

Does anyone have any idea what may be causing this or how I may remove/adapt to it?

Thanks,

Chris