serial output

[Newt2u]

Not sure if this is covered elsewhere, could not locate any information either here or in the V1.x.x documentation. I am running V1.2.0 on an RPi3. This problem was discussed in a more general thread but because of my inexperience, the discussion was a bit unfocussed. Here is the problem in more precise terms.

I would like to output RMC NMEA sentences to my autopilot via a usb/serial converter. RMC is input to kplex via the "system" UDP connection from iSailor/iPad on port 10110 (this is working). In particular, I want to filter out all AIS NMEA messages also input to kplex and output via signal K to OpenCPN.

1. If I set up a serial connection and assign it to kplex, where it could be filtered, it is automatically treated as an input, which is not what I require. I have tried editing that in the advanced setting to an output but have only managed to hang the kplex process in doing this and get no output to the usb to NMEA dongle.

2. If I assign it to NMEA output, I assume from the connection diagram that this assignment is to the signal K server and hence that would get all data output from kplex on localhost:30330, which includes the AIS data. When I do this I get output on the serial dongle but there seems to be no way to filter this data.

3. It was suggested I could output to serial via OpenCPN which would allow filtering but this is not an ideal solution as I only want OpenCPN as a backup to isailor/iPad in the saloon.

So my questions are:

1. Can I assign a serial output to kplex? Maybe my problem was editing a GUI setting rather than creating a new one; or


2. Can I filter data in system K to the serial output?

[Newt2u]

Update

I do have a solution to 1. now. It seems the crash was being caused by editing a manually edited kplex setting in the GUI to add filtering. When I added the filter in advanced settings. I managed to get exactly what I want from kplex on the serial/usb link.