The AMI MD71 Transmitting Magnetic Compass (TMC) System is an advanced Transmitting Magnetic Compass (TMC) designed to convert a vessel’s magnetic compass heading into highly accurate NMEA 0183 digital heading data. The system enables the ship’s magnetic compass to provide heading information to heading repeaters, radar, ECDIS, AIS, autopilot, VDR, and other navigation equipment. It replaces traditional optical reflector systems with modern electronic heading displays, offering simple installation, automatic calibration, and excellent accuracy for both newbuild and retrofit vessels.

Technical Specification

Parameter	Specification
Manufacturer	AMI Marine Ltd.
Model	MD71TMC
Equipment Type	Transmitting Magnetic Compass (TMC) System
Heading Source	Ship’s Magnetic Compass
Display Unit	MD71THD OLED Control & Display Unit
Display Type	2.7-inch High-Contrast Yellow OLED (128 × 64 pixels)
Sensor	MD52A/B Magnetic Compass Sensor
Sensor Processor	MD97CSP Compass Sensor Processor
Heading Output	2 × NMEA 0183 Output Channels
Output Sentences	HDT, HDG, HDM
Communication Standard	IEC 61162-1 / NMEA 0183
Heading Resolution	1°
Heading Accuracy	≤ ±0.5° (after calibration, sensor dependent)
Calibration	Automatic Sensor-to-Compass Calibration
Deviation Correction	Manual Magnetic Deviation Correction
Variation Correction	Manual Magnetic Variation Entry
Power Supply	24 VDC
Power Consumption	6 W
Audible Alarm	Built-in Sounder
Display Unit Dimensions	96 × 96 × 35 mm
Display Unit Weight	0.50 kg
Sensor Processor Dimensions	146 × 64 × 41 mm
Sensor Processor Weight	0.35 kg
Sensor Dimensions	Ø69 × 18 mm
Sensor Weight	0.12 kg
Display Protection	IP54
Sensor Protection	IP65
Operating Temperature	-15°C to +55°C
Storage Temperature	-25°C to +70°C
Compass Safe Distance	50 cm
Mounting	Panel Mount (Optional Trunnion Bracket)
Compliance	IEC 60945, IEC 61162-1, RoHS