Sea Tel 9797A-27, Инструкция по установке и эксплуатации

Страница: 41 / 93

9797A-27 C-Band TXRX Maintenance and Troubleshooting
7-5
decimal numbers ( v 1111 2222 3333 ). The numbers represent the Cross Level and Level Tilt Sensor
outputs and the azimuth encoder respectively.
The Cross Level Tilt display should be 2048 when the level cage is level. It should decrease
when the antenna is tilted to the left and increase when tilted to the right.
The Level tilt display should be 2048 when the level cage is level. It should decrease when the
antenna is tilted forward (EL down) and increase when tilted back (EL up).
The Encoder display will show 2048 in the center of the mechanical range (Relative 360.0),
decrease in value as the antenna is rotated counter-clockwise (down to about 0102 at lower stop)
and increase in value as the antenna is rotated clockwise (up to about 3994 at upper stop) .
7.3.5. Open Loop Motor Sensor Test
The ACU provides a means for monitoring the output of the 3 solid state rate sensors and the 3 reference
sensors for diagnostic purposes. The rate sensors and reference sensors are the primary inputs to the
PCU for stabilization.
To monitor the rate sensors, select the REMOTE COMMAND window on the ACU by pressing the MODE
key several times. Key in "
.119 ENTER " (note the decimal point). "w0000" should appear in the
command window. Press the MODE key once more to display the REMOTE MONITOR window. The
lower display will show "w" and three 4 digit decimal numbers (w 1111 2222 3333) . The numbers
represent the Cross Level, Level and Azimuth rate sensor outputs respectively with an nominal display of
2048. The Cross Level display should decrease when the antenna is tilted to the left and increase when
tilted to the right. The Level display should decrease when the antenna is tilted forward and increase
when tilted back. The Azimuth display should decrease when rotated CCW and increase when rotated
CW. The display change occurs during movement and returns to nominal when movement stops.
7.3.6. Open Loop Motor Test
The ACU provides a means for driving each individual torque motor to test that motors functionality. By
driving each axis and observing the resulting motion of the antenna, a coarse operational status of the
motor and motor driver can be established.
To manually drive the motors, select the REMOTE COMMAND window on the ACU. Key in " .94 ENTER "
(note the decimal point). "^0000" should appear in the command window. To drive the Cross Level motor,
key in 1064, 1128 or 1192 to drive the Cross Level axis left, off and right respectively. To drive the Level
motor, key in 2064, 2128 or 2192 to drive the level axis forward, off or back. To drive the Azimuth motor,
key in 3064, 3128 or 3192 to drive the azimuth axis CW, off or CCW.
7.3.7. To Disable/Enable DishScan
To be able to use Step Track, or to revert to Conscan, as your active tracking mode you will have to
disable DishScan.
To toggle the ON/OFF state of DishScan, select the REMOTE COMMAND window on the ACU. Key in
"
.94 ENTER " (note the decimal point). "^0000" should appear in the command window. To toggle the
current DishScan state, key in 67 and hit the ENTER key. If DishScan was ON it will now be OFF, if it was
OFF it will now be ON.
If DishScan is OFF and the Step Integral parameter is set to 0000 , you will get a constant ERROR 0016
(DishScan error) and you will see zeros flashing in the lower left of the Azimuth and Elevation ENTRY
menu displays. This is a visual indication that DishScan is turned OFF.
7.3.8. Satellite Reference Mode
In many cases, a corrupt or non-existent ship’s gyro compass input can cause tracking errors that are
large enough to cause the antenna to be mis-pointed off satellite.
Satellite Reference Mode will uncouple the gyro reference from the azimuth rate sensor control loop. In