Whilst the NT951G and NT991G MK2 autopilots are similar in appearance and apparently identical in terms of the parameters specified below, it should be noted that the software structures differ significantly to reflect the steering and response characteristics of vessels up to approximately 2000 grt (NT951G) compared with larger vessels from approximately 2000 grt upwards (NT991G MK2).

Certification Standards: -

Fully Type Approved to ISO 11674 & IMO A342 (IX) as amended by MSC64/67 Annex 3.
Wheelmarked in accordance with MED 96/98/EC

Autopilot Input / Output Specifications


Inputs: -				Outputs: -
Supply Voltage Range	11-40Vdc			NMEA 0183 Heading Data (Isolated RS422)
Power Consumption	2.5W (@24Vdc)			Update Rate	Selectable @ 1Hz, 10Hz or 20Hz
Illumination Max	8.1W (@24Vdc)
				Sentence Types (Mag/Gyro versus Update Rate)	Hz	Mag	Gyro
Mag Heading Input Ports: -					1	HCHDM
Navitron Heading Sensor Coil mounted above or below existing Mag compass	Coil type HSC1 or HSC2
						HCHDG	HEHDT
						APHDM	AGHDT
						APHDG
					10	HCHDM (5Hz)	HEHDT
Resolution	0.25°					HCHDG	AGHDT (5Hz)
					20	HCHDM	HEHDT
NMEA 0183 Heading Sentence from Electronic Compass (Priority and max update rate as shown)	XX HDM		25Hz	Resolution	0.1°
	XX HDG		16Hz	Autopilot status data	1	APRSA APHTD	AGRSA AGHTD
	XX HCC		28Hz	Furuno Heading Format: -
	XX HDT		25Hz	Update Rate		Selectable @ 5Hz or 40Hz
Resolution	0.1°
				Resolution		Selectable @ 0.166° or 0.1°
Gyro Heading Input Ports: -
Isolated 1:1 Synchro (if available in Gyro)	400Hz Excitation from Autopilot			Signal Amplitude		Selectable @ 5Vdc or 12Vdc
Resolution	0.25°
				Step by Step Heading Data: -
NMEA 0183 Heading Sentence from Gyro or optional NT925HDI (Priority and max update rate as shown)	XX HDT		25Hz	Steps per degree		Selectable @ 3, 6, 12 or 24
	XX HDM		25Hz
	XX HDG		16Hz	Signal Amplitude		5Vdc
	XX HCC		28Hz
Resolution	0.1°			Navitron Custom Serial Heading Data: -
				(to Navitron Digital Repeaters)
Follow Up Rate (Minimum): -
All Heading Input Types	30° / Sec			Navitron Serial Input/Output Data: -
				(to / from Navitron Bowthruster Interface, Analogue Steering & Dual Steering Interface options)

NT991G MK2 Heading to steer data accepted (from GPS/Plotter etc. for Track mode use)

NMEA 0183 Sentence types	XX HTC			Solid State Solenoid Switching: -
	XXHSC			Polarity		Selectable @ Common +VE/-VE
	XXAPB
				Max Rating		5A (11-40Vdc)

				Panel Alarms: -
Operating Temp Range	-20 to +60 °C			Power Fail	(int / ext supply fail)
				Steering Fail	(no rudder response)
Operator Controls & Selectors: -				Heading Input	(no heading data)
Yaw		Alarm Test/Cancel		Deg / min/sec	(ROT Status)
Rudder		Autotrim On/Off		Off Course	(specified limit exceeded)
Counter Rudder		Turn Rate		Rudder Limit	(specified limit reached)
Rudder Limit		Off Course Alarm level		Remote	(remote station engaged)
Illumination		+1° / -1° keys (NT951G)		Alarm Test	(tests all alarms)
Mode Switch		OR
Gyro/Mag Selector		Cancel/Confirm keys (NT991G MK2)		Mechanical	NT951G/991G MK2 Control Unit
				Width	297mm
				Height	176mm
Compass Safe Distance: -				Depth - behind bezel	110mm
NT951G/991G MK2 Control Unit	0.6m
				Weight	3.3Kg