COBHAM Sea Tel 9711-56 IMA C Band, Installation Manual

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Sea Tel 9711-56 IMA Maintenance
17-13
EAR Controlled - ECCN EAR99
17.4.1. Fine Balance and Monitoring Motor Drive Torque
The GRAPHS DISPTC graph chart provides a means for monitoring torque commands required for
each motor for diagnostic purposes and verifying antenna balance. By observing each trace, the
required drive of the antenna via the motor driver PCB may be established.
• To view the Torque Commands, select the graph chart.
•
This chart displays the Torque Command errors for each axis via three traces, CL (Cross
Level), LV (Elevation), and AZ (Azimuth), at a fixed 0.195 amps/vertical division.
•
In all axes, tracing centered on the reference line means that that axis is neutral. Tracing
above the reference line means that that axis is driving CCW. Tracing below the reference
line means that that axis is driving CW.
•
A normal trace display will be ± 1 divisions from the red reference line while under calm sea
conditions and with DishScan® Drive turned off. See example below
•
The Cross Level displayed above the reference line indicates that CL is driving CCW (Left).
Example: The antenna pictured in the screen capture below is imbalanced so that it is “Right
Heavy”. The CL trace is plotting above the red reference line (indicating that drive CCW is
required to keep the Cross-Level beam level (to the horizon).
• The Level display will plot below the reference line when the antenna requires CW drive (Up
in elevation).