User's Manual

Model 1150A DVOR
2-42 Rev. - November, 2008
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to others for any purposes without written permission from SELEX Sistemi Integrati Inc.
Figure 2-15 AC Power Monitor Block Diagram
2.3.2.14
Local Control Unit Theory
Refer to Figure 2-16. The Local Control Unit (LCU) controls the normal operation of the VOR. All operational
functions are performed by the LCU and are controlled by either front panel keyboard when in the local mode or by
the Remote Maintenance Subsystem (RMS) through the parallel interface. The LCU is controlled by the Portable
Maintenance Data Terminal (PMDT), Remote Control Status Unit (RCSU) or Remote Status Unit (RSU) through
the RMS for all remote operator intervention or by the RMS for automatic restart. The LCU receives the alarm
outputs from the installed Monitor circuit card(s) and depending on the configuration of the system, uses the results
of these signals to determine alarm status. If an alarm is detected, the LCU shuts down the system currently
radiating and transfers to the standby system in accordance with the system configuration. The LCU also provides
the ability to disable monitors and bypass alarms as required by the operator.
The LCU provides +24V to the two possible synthesizer VCO circuits, the +24V to activate the transfer switch, and
the transmit enable clock to the installed Audio Generators.
Status is reported by LED's visible to operator standing in front of the VOR, or through the RMS to the
PMDT/RCSU/RSU. An alarm shutdown is reported to the RMS as well as indicated by an audible alarm.