Navitron
Systems Ltd
Heading Data Interface
Type NT923HDI

Suitable for stand alone (independent system) use, the NT923HDI (Heading Data Interface) provides two channels of 10Hz NMEA 0183 heading output data and one Navitron serial output derived from a Navitron Heading Sensor Coil (HSC1 or HSC2) mounted above or below a good quality externally gymballed ships magnetic compass.

The magnetic information received from the compass via the Heading Sensor Coil can be electronically corrected for deviation during installation and the resultant heading permanently displayed and transmitted at a fixed 10Hz update rate in the following NMEA sentence types (from software version 2.0 onwards) : -

$HCHDT, $HCHDM.

Both sentences include checksum and are continuously transmitted at 10Hz on both NMEA output channels. The output channels are electrically isolated from the Ships supply and opto isolated to eliminate receiving equipment common mode connection problems.


Built in alarm functions triggered by internal monitors warn of magnetic data (input signal) and NMEA output data failure.

An internal power monitor relay provides a volt free normally open (NO) or normally closed (NC) contact to warn of power supply failure (contact ratings 0.5A @ 125Vac, 1A @ 30Vdc).

Suitable for 11 - 40Vdc power supply connection, the NT923HDI can be powered up directly via its panel mounted ON/OFF switch or from a remote location via remote power up terminals provided.

NT923HDI Technical Specifications

Heading & Speed Data Interface Leaflet Download (PDF)

Click for the NT923HDI PDF Manual


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