Sea Tel ST144-21, Installation And Operation Manual

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ST144-21 C/Ku-Band TVRO Maintenance and Troubleshooting
13-23
The “REMOTE BALANCE” parameter (located at the end of the Remote Parameters after REMOTE TILT) of the
ACU. When enabled, Remote Balance Mode temporarily turns DishScan®, Azimuth, Elevation and Cross-
Level drive OFF. This function is required when trying to balance antenna systems that have a built-in brakes
on the elevation and cross-level motors.
Assure that Antenna power is ON and that the antenna has completed initialization.
At the ACU:
1. From the ACU - REMOTE BALANCE parameter: Enable balance mode (refer to your ACU manual).
The screen should now display “REMOTE BALANCE ON”.
At the Antenna:
2. At the Antenna: Balance the antenna with the elevation near horizon (referred to as front to back
balance)
by adding, or subtracting, small counter-weights
.
3. Then balance Cross Level axis (referred to as left-right balance)
by moving existing counter-
weights from the left to the right or from the right to the left
. Always move weight from
one location on the equipment frame to the same location on the opposite side of the equipment
frame (ie from the top left of the reflector mounting frame to the top right of the reflector
mounting frame). Do NOT add counter-weight during this step.
4. Last, balance the antenna with the elevation pointed at, or near, zenith (referred to as top to bottom
balance)
by moving existing counter-weights from the top to the bottom or from the
bottom to the top . Always move weight from one location on the equipment frame to the same
location on the opposite side of the equipment frame (ie from the top left of the reflector
mounting frame to the bottom left of the reflector mounting frame). Do NOT add counter-weight
during this step.
5. When completed, the antenna will stay at any position it is pointed in for at least 5 minutes (with no
ship motion).
6.
Do NOT cycle antenna power to re-Initialize the antenna. Return to the ACU, which is still in
REMOTE BALANCE mode, and press ENTER to exit Remote Balance Mode. When you exit Balance
Mode the antenna will be re-initialized, which turns DishScan®, Azimuth, Elevation and Cross-Level
drive ON.
13.8.2.
The antenna is not able to self-calibrate the exact center value of its tilt sensor, which provides the antenna
with a two dimensional reference to the horizon, therefore it may be necessary to perform a
“REMOTE
TILT”
calibration. This procedure describes the steps involved in this calibration process from either the ACU
front panel or DacRemP diagnostic software by connecting the ACU’s RS-422 M&C Port to an available serial
port on a Laptop/Desktop computer using a standard 9-pin serial cable.
Remote Tilt:
(
NOTE:
Steps 2-7 will require one person above decks observing the antenna and another person below
decks to operate the ACU simultaneously)
Step 1:
Turn Off DishScan Drive.
Using the DAC2202 ACU Front Panel
•
Go to Remote Command window by pressing and holding the two
LEFT
&
RIGHT
arrows
until the EL TRIM parameter is displayed.
:
•
Press and release both
Left
&
Right
arrow keys again. The “SAVE NEW PARAMETERS” window
should now be displayed.
•
Press either the ENTER key or the DOWN key until the “REMOTE DishScan TG”
parameter is displayed.
•
Press the “
RIGHT
arrow to activate selection, then press the Up arrow to toggle state to
OFF. Press the ENTER key (Note: You will see that an error code 16 generated when
DishScan movement is off.)