Specifications

14
CONNECTION FOR NON-1001 FLUXGATE COMPASSES
PLUG PIN
NUMBERS
1001
FLUXGATE
COMNAV
FUNCTION
NON-COMNAV
CONNECTIONS
1 BLUE COSINE COSINE *
2 RED DRIVE P1 N/C
3 BLACK DRIVE P2 N/C
4 SHIELD GROUND GROUND
5 WHITE REFERENCE REFERENCE
6 YELLOW SINE SINE *
7 GREEN +12V +12V
* If the reading is reversed, swap these two wires.
!
In testing, the Brookes and
Gatehouse Halcyon 3 compass proved
to have a 'floating' reference. The
reference from the autopilot is also
'floating'. In order for the interface to
work, one of the references must be
fixed to a voltage. The reference is fixed
to +2.5 Volts inside the autopilot by
selecting Compass Type 3 (CPS.3)
during the Dockside Set-up. Compass
Type 2 (CPS.2) should be selected for all
other fluxgate compasses.
!
If the reading on the Digital
Display of the autopilot increases when
the heading of the vessel is decreasing,
reverse the Sine and Cosine leads.
!
If the reading on the autopilot
display does not agree with the vessel's
actual heading, place the Master Select
Switch on the autopilot in the
STANDBY
position and press the
ADJUST
key
twice to display the compass offset. Then
press either the up or down
ARROW
key
to adjust the offset by the amount of the
error.
!
If the compass is self-
compensating, do not run the autopilot
compensation routine during Dockside
Set-up (press either the up or down
ARROW
key when 'CAdJ' is shown on
the display).
!
If the compass is not self-
compensating, run the autopilot
compensation routine to correct the
compass during Dockside Set-up (press
the
ADJUST
key when 'CAdJ' is shown
on the display).
MAGNETIC COMPASS
!
The advantage of using a
magnetic compass with a fluxgate sensor
is that the autopilot is sensing the
position of the magnets on the compass
card rather than sensing the earth's
magnetic field directly.
!
As the card of the compass has
physical inertia, it does not react
immediately to the changes in the
magnetic field it is immersed in, but only
to those changes which persist long
enough to overcome the resistance of
the compass card to movement.
This means that the compass is a more
stable heading reference than a fluxgate
compass. The magnetic compass will
largely ignore changes in the magnetic
field in the plane of the compass card
caused by vessel motion that the fluxgate
compass will react to.