ST94-21 C/Ku-Band TVRO
Setup – Ships Gyro Compass
5-1
5.
Setup – Ships 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 ACU 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). In normal
operation when viewing and ADMC recording in DacRemP, the “Relative Azimuth” trace should do exactly equal & opposite to
whatever the Heading trace does and the “Azimuth” trace should stay flat.
In normal operation the heading display in the ACU should at all times be the same value as the reading on the Gyro Compass
itself (this is also referred to as Gyro Following.).
If the ACU is not Following the Ships Gyro Compass correctly (un-erringly) refer to the Troubleshooting Gyro Compass
Problems.
5.1.
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 0002 so that the ACU 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. The acceptable settings
are:
362
for 360:1 Synchro with S/D Converter
90
for 90:1 Synchro with S/D Converter
36
for 36:1 Synchro with S/D Converter
2
for Step-By-Step gyro or NMEA gyro
1
for 1:1 Synchro with S/D Converter
0
for No Gyro linear AZ Search Mode (No Heading input available)
5.2.
Updating the GYRO TYPE parameter
To manually update, press the LEFT arrow key to bring the cursor under the least significant character. Continue to
move the cursor until the desired character to be edited is underscored (selected). Use the UP or DOWN arrow keys to
increment or decrement the selected character.
Use the LEFT or RIGHT arrow key to move the cursor left or right to select other characters to modify. When you are
finished modifying press ENTER to execute the new value OR press NEXT to abort and exit setup mode.
When you are finished making parameter changes, go to the SAVE NEW PARAMETERS display to save the changes you
have made.
5.3.
If There is NO Ships Gyro Compass
Without heading input to the system the ACU will
NOT
be able to 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. 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 0000, the SWEEP INC parameter to 0047 and SAT REF (Satellite Reference Mode) MUST be turned
ON.
This combination of settings will cause “No Gyro” Search pattern to be use to find the desired satellite (refer to the
setup – Searching lesson).
EAR Controlled - ECCN EAR99
Summary of Contents for ST94-21
Page 4: ...EAR Controlled ECCN EAR99 ...
Page 10: ...Table of Contents x This Page Intentionally Left Blank EAR Controlled ECCN EAR99 ...
Page 123: ...EAR Controlled ECCN EAR99 ...
Page 126: ...EAR Controlled ECCN EAR99 ...
Page 139: ...EAR Controlled ECCN EAR99 ...
Page 140: ...EAR Controlled ECCN EAR99 ...
Page 141: ...EAR Controlled ECCN EAR99 ...
