I have an autopilot Raymarine ST4000+ installed on my sail boat and a B&G
Network for speed and wind direction. I'm trying to send the NMEA data from
B&G to the ST4000. On the B&G instrument the output is a simple five holes
DIN connector. I've searched around for the wirings of this plug but it
seems the best kept secret (or I'm getting too old for this stuff).

Where could I find the description of the plug (without having to bring an
oscilloscope in the cockpit)?

Many thanks
Giuseppe