Simrad AP25 - Manual (Page 14)

Simrad AP25 Autopilot
12
20221495F
1.7 Heading Sensors
The AP25 autopilot can be used with the following combinations
of heading sensors:
RC36 Rate compass
Fluxgate compass with integrated rate sensor. Provides a dramatic
improvement to the dynamic performance of both the autopilot
and a stabilized radar display.
RC36 comes as standard with the autopilot.
RFC35 Electronic Fluxgate Compass
(optional)
A compact heading sensor from Simrad with 15 m (45 feet) of
cable. The direction of the earth's magnetic field is sensed by a
floating ring core in a fluxgate coil and transformed to a digital
signal read by the autopilot steering computer.
RFC35 can operate as a low cost back-up compass for the AP25
autopilot.
NMEA compass (optional)
A well performing compass that outputs NMEA 0183 HDT or
HDG messages at 10 Hz can be connected directly to the AC20
or AC40 autopilot computer.
The AC10 Autopilot Computer has no port for NMEA compass
input.
It is absolutely necessary for the autopilot that the heading rate is
minimum 10 Hz.
Simrad gyrocompasses
Depending on the model there is direct NMEA0183 interface or
you will need an optional GI51 interface unit to get NMEA0183
interface. Ask your Simrad dealer for information.