COBHAM Sea Tel 9711-56 IMA C Band, Installation Manual

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Sea Tel 9711-56 IMA Setup – Ship’s Gyro Compass
7-1
EAR Controlled - ECCN EAR99
7. Setup – Ship’s Gyro Compass
The Ships Gyro Compass connection provides true heading (heading of the ship relative to true North) input to the
system. This allows the ICU to target the antenna to a “true” Azimuth position to acquire any desired satellite.
After targeting, this input keeps the antenna stabilized in Azimuth (keeps it pointed at the targeted satellite Azimuth).
7.1. Setting the Gyro Type
The GYRO TYPE parameter selects the type of gyro compass interface signal, the appropriate hardware
connections, and the ratio of the expected input signal for ship turning compensation. Default GYRO TYPE
parameter for all systems is Step-By-Step so that the ICU will properly follow for Step-By-Step or NMEA gyro
signals.
If the Ships Gyro Compass output is Synchro, or there is NO Gyro Compass, the GYRO TYPE parameter must
be set correctly to properly read and follow the Ships Gyro Compass signal that is being provided. To
manually update the Gyro Type parameter:
1. Go to the Communications Interface
screen.
2. Click the Gyro Type drop down menu..
3. Select the correct Gyro type.
4. Click Save, located on the navigation bar
in the left area of the screen.
7.2. If there is NO Ships Gyro Compass
Without heading input to the system the MXP will NOT be able to easily target, or stay stabilized ON, a “true”
azimuth pointing angle. This will make satellite acquisition much more difficult and the true azimuth value
that any given satellite should be at will not be displayed correctly.
This mode of operation is NOT recommended for ships or any other vessel that turns in the water. A better
solution would be to provide a Satellite Compass (multiple GPS Antenna device) to provide true heading input
to the ACU. These devices are readily available and are much less expensive than a Gyro Compass.
If there is NO Gyro Compass (ie on a large stationary rig which is anchored to the ocean floor) set the GYRO
TYPE parameter to “No Gyro” or to “Fixed”.
Fixed mode is used when you do not have a gyro compass, but the ship/vessel/rig is stationary at a
fixed heading that you can manually enter for satellite targeting. This allows you to use a standard
(small) search pattern and acquire the satellite relatively quickly.