To my great surprise, while browsing through the instruction manual for the M506 VHF Marine Band radio, I discovered that ICOM has adopted the proper NMEA nomenclature for the signal names in the NMEA-0183 interface circuit. In my article Guide to NMEA-0183 Interconnections I wrote abot the confusion created by manufacturers when giving the NMEA-0183 signals random names instead of using the NMEA recommended nomenclature. ICOM is the first manufacturer I have seen that has followed the NMEA recommendation for the NMEA-0183 interface and used the proper names.
The NMEA-0183 interface on the IC-M506 radio is illustrated on page 101 of the manual as follows:
TALKER A = White
TALKER B = Brown
LISTENER A = Yellow
LISTENER B = Green
In addition to ICOM providing the proper names for the signals, they also have followed the NMEA-0183 v4.0 recommendation for the color coding of the wire insulation. Again, I believe this is the first instance of this conformance to recommended color coding that I have seen. ICOM is to be commended for implementing the recommended NMEA practices for signal name and wire color code in their new M506 radio. Let's hope more marine electronics manufacturers will follow this same path.