True heading data source required for AIS950

[Chuck - Raymarine - Moderator]

True heading data source required for AIS950

Unlike Class B AIS transceivers, Class A AIS transceivers are mandated by the IEC to be interfaced to a source of true heading data from a non-magnetic north seeking compass. In the case of the AIS950, the heading data must additionally originate from a source supporting NMEA 0183 communications protocol and must additionally include the HC, HE, or HN Talker ID within the NMEA 0183 HDT sentences which will be received by the AIS950. The most common sources of true heading data which meet this requirement are gyrocompasses and GPS compasses (ex. Furuno SC-30, Simrad HS60, SeaPilot Vector Compact GPS Compass, etc.). As most recreational autopilot systems, including those offered to date by Raymarine, are dependent upon magnetic north seeking heading sensors, heading data from most recreational autopilot systems sensors do not satisfy the requirements for a true heading data source mandated for Class A AIS Transceivers. While it is possible to configure some magnetic north seeking heading sensors (ex. Airmar GH2183, etc.) to transmit the NMEA 0183 HDT sentence described above, such sensors will not officially satisfy the mandate specified above.

RAYFAQ#