ComNav Commander P2 - All Compass Types; Calibrating for Compass Offset

ComNav Commander P2 & P2VS Installation & Operation Setting Up
Document PN 29010074 V4.1 - 101 -
Calibrating for Compass Offset
Even after your compass(es) are compensated for Deviation, they still may not be giving a
correct reading.
Any or all of them may have an individual fixed offset, so you must tell the P2’s SPU what
each one’s calibration value is.
Calibration is a simple matter of synchronizing each compass’s directional readings, as seen
by the SPU, to the actual Magnetic direction values of the Earth’s magnetic field.
All Compass Types
Bring the boat onto a known bearing and maintain it there by steering manually. The
autopilot should be in STANDBY mode.
1) Double-press the
S
S
T
T
A
A
N
N
D
D
B
B
Y
Y button to bring up the Standby menu. Select “Compass
Source”, and set it to the correct value for the first of your compasses:
• “Analog” for a Magnetic Sensor, a ComNav Fluxgate Compass (with or without HRS),
or a non-ComNav Fixed or Floating Analog Compass
• “Digital” for a 45° Compass
• “NAV1” for an NMEA compass connected to the IN-1 pins of the J9 – NAV I/O
connector.
• “NAV2” for an NMEA compass connected to the IN-2 pins of J9 - NAV I/O connector.
2) Move the highlight down one position to “Compass Cal”. Using the
C
C
O
O
U
U
R
R
S
S
E
E
C
C
H
H
A
A
N
N
G
G
E
E
knob, adjust the reading so that it agrees with the known bearing that the boat is on.
• Any changes simply increase or decrease the value stored in the P2’s settings
memory, by 1° per click of the
C
C
O
O
U
U
R
R
S
S
E
E
C
C
H
H
A
A
N
N
G
G
E
E knob.
• When you first set up your compass(es), the initial calibration value for each compass
is the value it was outputting at the time it was detected during Dockside Setup.
3) Move the highlight back to “Compass Source”, select the next type of compass you have,
and repeat step 2). Repeat for all your compasses.
4) Double-press the
S
S
T
T
A
A
N
N
D
D
B
B
Y
Y button to exit the Standby menu.
5) Verify that the compass heading shown agrees with the actual heading of the boat, and
stays steady, by holding a number of constant-heading courses for a few minutes each.
Note: NMEA compasses (e.g., the ComNav Vector G2/G2B GPS Compass) typically
do not require on-the-boat calibration. You should refer to the Installation &
Operation manual that came with your NMEA compass to verify this, however.
Even if your NMEA compass does require calibration, it may not be necessary to
set the value in the P2. Many – if not most – NMEA compasses can store their
own calibration value. If that is so, you should skip the steps below, and follow
the instructions that came with the NMEA compass.
However, if you wish to set a calibration value for an NMEA compass in the
autopilot, you may do so. Indeed, you may set two values – one for each of
NAV1 & NAV2.