ComNav Commander P2 - 45° Compass Transducer; Tri-Axis Rate Gyro Compass; Other Compasses; Figure 13 - 45° Compass Transducer

ComNav Commander P2 & P2VS Installation & Operation System Overview
Document PN 29010074 V4.1 - 34 -
This is particularly important in high latitudes, (such as Alaska, Labrador or the North Sea),
where the horizontal component of the earth’s magnetic field (which is the portion that the
compass is trying to detect) is very small relative to the magnetic field of the boat.
The disadvantage of the Magnetic Compass is that in very rough weather with the boat going
to windward, it is possible for the boat motion to upset or “tumble” the compass card,
disabling the Autopilot.
Because of the relative insensitivity of the Magnetic Compass to both the earth’s and the
boat’s vertical magnetic fields, it is recommended for use at latitudes higher than 50° (North
or South), and for use on steel boats when optional quadrantal spheres are included.
45° Compass Transducer
PN 20640006
The ComNav 45° Compass Transducer
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contains a fluid-damped fluxgate sensor and works
at heeling angles up to 45°. This compass puts out a proprietary digital Sine/Cosine signal.
It is wired directly to the SPU.
Figure 13 – 45° Compass Transducer
Tri-Axis Rate Gyro Compass
PN 11510001 (NMEA 0183 interface)
The ComNav Tri-Axis Rate Gyro Compass is a solid-state compass with NMEA 0183 or
NMEA 2000 interface. Its integrated three-axis accelerometer and three-axis rate gyro ensure
2° of accuracy in rough sea conditions when the vessel is pitching and rolling up to 30°.
Figure 14 – Tri-Axis Rate Gyro Compass
Other Compasses
ComNav recommends the use of ComNav’s own compasses for the best performance of the
Commander P2 Advanced Autopilot System – but you certainly may decide to use either a
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Note: the 45° Compass Transducer was discontinued early in 2008. There is no direct replacement available for it.
However, the Commander P2 will continue to support it. A 35° Compass Transducer (PN 20640007) is still available;
however, it does not always work properly with the P2 – depending on the vessel – and so such use is not recommended
or supported. It is wired the same as the 45° Transducer.