Sea Tel 4006-23 IN A 60" RADOME Installation And Operation Manual Download

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4006-23 Broadband At Sea

Maintenance and Troubleshooting

7-6

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:

Using the

LEFT/RIGHT

and

UP/DOWN

arrow keys set the Remote Command value to

^0000

" and press

ENTER

To drive the Cross Level motor, key in

1064,

1128 or

1192 and press

ENTER

to drive

the Cross Level axis LEFT, OFF or RIGHT respectively.

To drive the Level motor, key in

2064,

2128 or

2192 and press

ENTER

to drive the

level axis FORWARD, OFF or BACKWARD respectively.

To drive the Azimuth motor, key in

3064,

3128 or

3192 and press

ENTER

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.
Select the

DISHSCAN

parameter window on the ACU:

Press the RIGHT arrow, then press the UP arrow and last press the ENTER key to turn
DishScan mode ON.

Press the RIGHT arrow, then press the DOWN arrow and last press the ENTER key to
turn DishScan Mode OFF.

If you change this remote parameter, you must save the change using REMOTE PARAMETERS.
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

The ships gyro compass input to the ACU may be accurate and stable in static conditions and
yet may NOT be accurate or stable enough in some underway dynamic conditions. If there is no
gyro compass or if the input is corrupt, not stable or not consistently accurate the tracking errors
will become 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. When operating in Satellite Reference Mode changes in ships gyro reading will not directly
affect the azimuth control loop. The Pedestal Control Unit will stabilize the antenna based
entirely on the azimuth rate sensor loop and the tracking information from DishScan. This will
keep the azimuth rate sensor position from eventually drifting away at a rate faster than the
tracking loop can correct by using the tracking errors to regulate the rate sensor bias.
Satellite Reference Mode can be used as a diagnostic mode to determine if tracking errors are
caused by faulty gyro inputs.
Satellite Reference Mode

MUST be used when:

•

No Gyro Compass is available

•

Frequent or constant ACU Error Code 0001 (Gyro Compass has failed)

•

Gyro Compass output is NMEA heading

•

Flux Gate Compass is being used

•

GPS Satellite Compass is being used