Sea Tel ST88-21 C/Ku-Band TVRO, Инструкция по установке и эксплуатации

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Maintenance and Troubleshooting ST88-21 C/Ku-Band TVRO
13-16
changing to a logic level low when engaged. See below for a screen capture of an antenna that was
driven so that the Home Flag switch is engaged.
13.7.7. Open Loop Rate Sensor Monitoring
The DacRemP
DISPW
graph chart provides a means for monitoring the output of the three 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.
•
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 impracticality 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).