ZTC Autohelm Seatalk Autohelm Seatalk is a proprietary bus for communications between various intruments. Some of the instruments can act as NMEA-0183 talkers or listeners. Note that NMEA data can only be sent to, or received from, a SeaTalk system using AutoHelm's NMEA SeaTalk interface box, or those instruments that provide an NMEA-0183 interface. SeaTalk itself is not compatible with NMEA, and cannot be read with a normal PC serial port. Standard Sentences A talker typically sends a group of sentences at intervals determined by the unit's update rate, but generally not more often than once per second.
Checksums are optional for most sentences, according to the standard.
N,12311.12,W,225444,A 4916.46,N Latitude 49 deg. Longitude 123 deg. Magnetic 235.,M Heading 235 deg. HSC - Command heading to steer HSC,258.,T,236.,M 258.,T 258 deg. True 236.,M 136 deg.