The SeaClear software has a selection option in the same 'box' as AUTOMATIC ON/OFF and TRACK ON/OFF labeled something like SEND NMEA ON/OFF (without gps on my desktop, the label doesn't appear so I don't know exactly what the wording is). When a route is set and activated and the SEND NMEA is ON SeaClear will send the next waypoint (and I assume other nmea data) over the network through the USB to serial converter. The Raytheon converter box that is in the network will convert the nmea to seatalk and the radar display in the cockpit will show the next waypoint. Very nice setup...the laptop stays inside and I have the next waypoint displayed at the helm. All equipment is Raytheon except the laptop and serial/usb converter.
I have been unable to figure how to make OpenCPN software do the same thing.
Hope this helps, but I doubt that I have added much new information here....not sure what else to say.
How do I get OpenCPN to transmit route data/next waypoint?
Bruce, first make sure you understand your SW manual, and be sure NMEA transmition is activated. This is an "old" protocol and if present, I doubt it would contain any mismatched sentence where the target couldn't read. It looks rather a NMEA set-up mismatch only. If you have a standard ST60 like AP display, what that shows ? Can you still track a route ? Can you see other sentences (like BTW, XTE, etc) ? I would plug back the USB out to a RS232 terminal in (this a Windows feature on your laptop) and then search for the NMEA navigation sentences (this is text like), then would make sure you're using the appropriated serial setup (bps, parity, stop bits, etc ...) might be a simple adjust on your USB interface ....
One more thing, if you have a Ray autoplilot (like 4000 or any corepack) you could also remove the convertion box and run NME directly to it. Although your AP doesn't fully translate NMEA to SeaTalk (on old unities) this arrangement will remove a suspicious box and still provide 99% of translated information, more than sufficient to what you're looking for.
OK, considering NEMA feature might not be present at OpenCPN and if diagnose is not your style, then I suggest to contac Dave directly, he's the author of OpenCPN. Although a free SW, he might be interested in help you. He use to hove at Cruisers & Sailing Forums under "bdbcat" nickname. Good luck.