SeaSpace TeraScan 1.5M, Operation And Maintenance Manual

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SeaSpace Corporation
7.2.4.2 Tracking Positioner
The tracking sequence for data acquisition is sent from the computer to the PCU. The tracking positioner
receives commands from the PCU to move its four motors. The antenna dish levelness is determined by the
rate sensors.
When other functions such as antenna or ac are running, they can block these test commands from being sent
to the antenna.
Failures can be due to:
a. The PCU
b. Servo controllers (servos located inside PCU assembly on 6003AL)
c.
Servo motors
d. Drive belts
e.
Rate sensors in the level platform
f. Wiring harness
g. Connecting cable and connectors
h. Power supply
i.
Motor sprocket coming loose from the drive shaft
j. Incorrect antenna type (n0 xxx) in the PCU
Use the actual telemetry chain number in place of 1 in these diagnostics.
CONDITION TEST CAUSE ACTION
An error has been
detected by the PCU.
ac 1 S
ac 1 "&"
Error condition is
identified by PCU.
See following tests for
other causes of failure.
Replace unit (pot/motor/
level cage).
If problem still exists,
replace PCU {8.4.1}.
Enter PCU coefficients
{8.5.11}
Azimuth error during
operation.
ac 1 st
6003L:
Azimuth drive sprocket
[12574581] is loose.
Reseat screw in drive
sprocket.
Cable is caught, antenna
cannot turn in azimuth. Re-dress cables.
Azimuth drive motor is
bad.
Pedestal harness is bad.
Replace azimuth drive motor
{8.4.2}.
Replace pedestal harness.
Azimuth spins rapidly
on startup Rate sensor is bad. Replace level cage {8.4.5}.