For the technically inclined I found this guide to NMEA 183 while trying to sort out connecting Coastal Explorer to an S1000 RayMarine Autopilot. It was the first place where I found a reference to NMEA common on transmit and receive as being the same as signal ground on RS232.
http://www.bmea.org/wp-content/uploads/ ... -guide.pdf
I think there is one mistake in a drawing where NMEA IN DATA and NMEA IN Common are reversed.
http://www.bmea.org/wp-content/uploads/ ... -guide.pdf
I think there is one mistake in a drawing where NMEA IN DATA and NMEA IN Common are reversed.