Datamarine 5000/5100 protocol?

[johnfreed0]

Folks,

I’ve got a Datamarine 5100 the masthead unit of which I’d like to interface with an autopilot. It turns out that the 5100 doesn’t speak any dialect of NMEA or any other digital protocol. I’d like to build a translator from 5100 speak to NMEA so that I could get wind direction and speed.

The interface to the remote is a coaxial cable which puts out an analog signal. I contacted DMI, which is the current avatar of Datamarine, and was told that there was no documentation on these units that would give me any insight into what’s being said. They suggested that I take my trusty oscilloscope and try to decode the signal.

Granted that life in the islands lends itself to patience but I’m getting old and may not survive long enough to crack the code. Does anyone have service manuals or knowledge of how I can get the masthead information in some reasonable format?

Thanks,
John Reed
S/V Langsam