Thanks for your reply. I’m afraid I have very little useful information on the ST60 Multi other than the manual, and that barely mentions NMEA. I read its NMEA 0183 on a forum somewhere, so its not definite. I knew about NM|EA 0183 and NMEA 2000 & NMEA over TCP/IP, but I didn’t realise there were variations of NMEA 0183. I suppose that’s the wonderful thing about standards….there are so many of them!

I am happy to try the Garmin bridge and see if that works. I used to work with RS232 and RS485 many years ago, so if the bridge doesn’t work, I’ll dig out my old diagnostic tools and trawl the archives for notes….

Thanks again,

Kevin.