Class B installs #1, Brookhouse solution
A nice thing about Class B AIS transponders, I think, is that by regulation they include a GPS and thus they deliver “own vessel position” along with AIS target info to whatever displays they feed. But that can present an issue if you’re adding Class B to a system that already has an NMEA 0183 or a SeaTalk GPS attached. Brookhouse seems to have a neat multiplexer solution that makes the new GPS a backup ready to automatically take over if the vessel’s regular GPS fails…
The trick is a Brookhouse multiplexer feature called “NMEA data manipulation”, which is controlled by user uploaded scripts. It’s usually used to filter and translate NMEA sentences, but Brookhouse recently added something called “conditional wipe” which removes GPS data from an AIS input stream only if the primary GPS is producing lat/lon data. And because some Brookhouse multiplexers (like the one below) can handle SeaTalk, this feature can also work with Raymarine’s proprietary GPS sensors.
It could well be that other NMEA 0183 multiplexers—like maybe some Shipmodul or Actisense models—can enable the similar auto redundancy, and of course redundancy and multiplexing are both well supported for NMEA 2000 transponders like the ones from Simrad. And, yes, there really is a Furuno FA50 Class B transponder (commented on here) that has an Ethernet output and built-in Web server. I hope to test it soon, along with some other Class B’s. We’re done to install details!