Sea Tel 9497B-21, Installation And Operation Manual

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9497B-21 C/Ku-Band TVRO Maintenance and Troubleshooting
7-17
7.7.7.
The DacRemP
DISPW
graph chart provides a means for monitoring the output of the 3 solid state rate
sensors (located inside the Level Cage Assembly) for diagnostic purposes. The rate sensors are the primary
inputs to the PCU for stabilization.
Open Loop Rate Sensor Monitoring
•
To monitor the rate sensors, select the graph chart
•
This chart displays sensed output from the 3 rate sensors via three traces, CL (Cross Level), LV
(Elevation), and AZ (Azimuth), at a fixed 1
º
/Second/vertical division.
•
A normal trace display will be
±
1 divisions from the red reference line. The example shown below
shows an antenna that is NOT currently sensing motion in any axis.
•
The Cross Level display should decrease (plots below red line) as the antenna is tilted to the left and
increase (plots above red line) as the antenna tilted to the right.
•
The Level display should decrease (plots below red line) as the antenna is tilted forward and increase
(plots above red line) as the antenna is tilted back.
•
The Azimuth display should decrease (plots below red line) as the antenna is rotated CCW and
increase (plots above red line) as the antenna is rotated CW. In the example below, the output of
the Azimuth rate sensor is plotted above the reference line, indicating that the antenna was driven
CW in Azimuth. Due to the in-practicality of driving an axis at a consistent rate, verification of rate
sensor output is, for the most part restricted to a positive or negative response of the Level Cage
movement (plotting above or below the red reference line of each axis).