NMEA 2000

[Toubab]

Originally Posted by twistedtree

Keep in mind that in anything other than the simplest N2K network, these N2K to 01830 converters are problematic, and it takes a lot more than just a driver to pass data to really support N2K in OCPM or any other device. The crux of the issue is around instancing when you have multiple devices of the same type.

The beauty of N2K (or one of them) is that you can have multiple GPSs, Nav sources, etc on the same network, and via configuration decide which device gets used by who, reconfigure in the event of a failure, and often times configure for automatic fail-over. With 0183 these things require rewiring.

But N2K devices need to support these configuration operations to be fully functional. For example, if you have two GPSs on your N2K network, and use an N2K to 0183 converter to get that data to OCPM, somehow you need to be able to tell the converter which GPS to use. I suspect most converters lock onto the first GPS they hear and stick with it, ignoring the other. Hopefully they will automatically pickup the second GPS if the first one goes silent, but who knows.

In a fully functional N2K system, you should be able to select the primary GPS, and ideally designate a secondary, tertiary, etc. Then you can be sure that your high-precision sat compass/GPS is used, not the cheapo backup. And you can be sure the Sat compass is used for heading info, not the less precise rate compass.

When OCPM adds N2K support, hopefully all this will be taken into account. Again, it doesn't matter if you only have one of each device type, but I'd argue that two GPSs is pretty commonplace, and more serious cruising boats will often have redundancy in all vital nav components. For eample, most Nordhavns 47' and up have fully redundant auto pilots (two rudder feedback units, two compasses, two AP computers, multiple control heads, etc). Most will have a Sat compass (3rd heading source) which is also a GPS, a backup GPS, AIS which has yet another GPS source, etc. It's not for everyone by any means, but for OCPM to be viable on such boats it will need to handle all this when it adds N2K.

I'm planning on having a very simple N2K network and my boat is only going to be doing some coastal cruising and maybe a little island hopping, so I should be fine.

Has there been any talk about when OCPN might support N2K?

[Littlechay]

Originally Posted by bcn

It just needs a developer and some coding to get it into OpenCPN.

Just, indeed

[iron9]

Great post. I just learned why my Actisence NGT-1 won't work with OpenCPn. However, it doesn't work properly with my "PC Plotter 5000" program either. I get all data from my the NMEA 2000 network (HDS-9/AP24) except Heading. Looks quite stupid when boat symbol moving sideways.
But I can't share WP:s, routes or tracks or steer AP from PC.

Regards
JA