CONTROL MONITOR, C 11291 SERIES.
The control monitor is used to monitor and control a radio. When the RT FCTN switch is placed in REM,
the control monitor controls the RT. A total of three RT's can be monitored and controlled by a single
control monitor. The third RT is cabled to the first control monitor (CM A) at connector J2. A second
control monitor (CM B) can be used by installing a CX 13290/VRC cable between the J3 connectors of
both CM A and CM B. Only one control monitor can control the radio at any given time and control must
be passed back and forth. The control monitor controls the selected RT using frequency shift keying
(FSK). The control monitor is under microprocessor control at all times.
VAA AM 7239 SERIES
CX 13290/VRC CABLE
CX 13290/VRC CABLE
The microprocessor monitors the front panel for any change in switch settings. The FCTN switch, in
conjuction with the INIT switch, starts all control signals to the RT. The control monitor will control the
function, mode, RF power output, channel selection, and cipher or plain text. There are no provisions in
the control monitor for controlling individual frequencies or frequency offsets. This may be done only at
the RT keyboard.
The control monitor can test its operation similar to the RT by setting the FCTN switch to the TEST
position. In TEST, the control monitor checks the internal programming and circuitry. Gd" is displayed if
the control monitor is good. If the control monitor is bad, an F1" or F2" will be displayed. Testing
continues and displays are repeated until the FCTN switch is moved from the TEST position. Self test is
run automatically when power is first applied to the control monitor. Other displays seen during
operation indicate failures. F7" is displayed on the control monitor if an incorrect response is received
from the RT. This may occur if the RT FCTN switch is moved out of REM, or if there is a failure in the
communication link. Fr" (failed response) is displayed if two control monitors are installed, and an
incorrect response is received. Either of the control monitors or the interconnect cable can be faulty. Er"
typically indicates that the operator made an error in operation. The CHAN display may blink when all
other displays are normal. This occurs if the user has not loaded the selected channel with an SC
frequency or FH hopset. If a frequency or hopset is loaded and the CHAN display blinks, the RT is bad.