Simrad RC37 User Manual

20221370A 1 07.06.04

RC37 RATE COMPASS

INTRODUCTION

Simrad RC37 Rate Compass is a fluxgate compass with a built in rate sensor that
significantly improves the dynamic performance of the compass. This makes it an
excellent heading source for autopilots, chart plotters, radars and other equipment that
will benefit from the dynamic characteristics of RC37.

Heading output is on sine/cosine and NMEA0183 formats.

The technical specifications are printed on page 4.

The RC37 Rate Compass (part no. 22084446) can be used as a high performance
heading sensor on the following Simrad or Robertson autopilots: AP45 and AP9MKII –
Mk3. It replaces the previous RFC35RS and is a high performance alternative to
RFC35N and RFC35NS.

RC37 comes with a 15 m (49’) open end cable wired for NMEA0183 input and output.
The internal connections of the wires are shown on Figure 2.

Notes !

1. Figure 2 shows the connections when the compass is used as a stand alone

NMEA compass. An extra cable gland is supplied for a separate supply
cable if preferred. Disconnect the grey and pink wires from TB4 and
connect the separate cable wires instead

2. For connection to IS15 instruments refer to revision C or later of the IS15
NMEA manual.

3. On AP45 and AP9MkII – Mk3 installations you need the compass connector
kit part no. 22088413. Connect the AMP connector (J2, J5) from the kit as
per Figure 3.

INSTALLATION

The RC37 contains a magnetic fluxgate sensor and great care should be taken when
deciding the mounting location.

Figure 1 Mounting

RC37 Rate Compass

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Select a location that provides a solid mounting place free from vibration and as close to
the vessel's centre of roll and pitch as possible, i.e. close to the water line. It should be
as far as possible from disturbing magnetic influences such as engines (min. 2 meters),
ignition cables, other large metal objects and particularly the autopilot drive unit.

The compass must be mounted horizontally. When the compass is deck mounted and
equipment connected to the compass has no off-set compensation, provisions should be
made to allow for mechanical alignment. In that case the compass must also be mounted
with the cable gland pointing aft.

Use the supplied mounting kit and drill holes through the centre of the slots.

Note ! The compass face plate on the RC37 is the TOP. Never mount it upside down!

On steel hull boats it should be mounted on a non-ferrous pedestal approx.

0.9 m (3 ft.) above the wheelhouse.

ELECTRICAL CONNECTIONS

RC37 is wired for NMEA connections, See Figure 2. When connected to autopilots it
must be rewired as per Figure 3 to provide heading output on sine/cosine format (swap
the wired and the unwired terminals) A separate cable gland is supplied for a second
cable that can be used for additional heading output on NMEA0183 format. See Figure

2.

Electrical connections NMEA0183 output stand alone compass

Figure 2 Stand alone NMEA compass