Simrad GI51 Gyro Interface
6
20221594 / Cb
2.5
Heading offset adjustment and alignment
For a synchro type gyro compass, offset adjustment is normally
done once during installation. Before making a correction, make
sure that offset is not caused by wires connected in the wrong
order (ref. section 2.7).
When connected to a Simrad autopilot via Robnet, offset
adjustment is done in the autopilot Seatrial menu. When
connected to a Seatex AI80, offset adjustment is done at the
operator panel. For stand alone unit, offset is adjusted as
described further down.
A gyro compass with step or geared synchro will require heading
alignment after power-on and after a fault on the compass signal
to GI51.
When connected to a Simrad autopilot via Robnet or Seatex AI80,
alignment is prompted for on the display of the operator panel.
Note!
Before alignment is commenced, there will be no NMEA HDT
output (only proprietary NMEA data).
As stand alone unit both installation offset and alignment can be
done either by proprietary NMEA data (ref page 19) or by an
external switch connected between
SEL 3
and
+12V
terminals on
TB12.
+12V
SEL.1
SEL.3
SEL.2
SEL.4
SE
L
E
CTO
R
TB12
The switch must be a potentional free pulse type. When pressing
and holding the switch, the heading will increase or decrease,
depending of last direction control.
The heading will increase in a slow rate for the first 3 degrees,
but change to high rate for as long as the switch is depressed. By
making a quick double press and keep the last press, the
direction is reversed and started with low rate. Single presses on
the switch changes the heading by one tenth of a degree.
The switch should be mounted in a location for convenient operation.
Note!
Make sure that the switch is mounted on a protected area to
avoid unintended operation that may give large heading
changes!