TM 11-5820-890-30-4
2-18. FILL OPERATION. Continued
SIGNAL
FUNCTION
AR/CCD
(Audio Receive/Command and Control Data) The AR signal is switch
separated from CCD in the ICOM data I/O module. CCD gives
commands to the COMSEC module when that module is under the
control of the fill device. Otherwise, this line is used to pass commands
to the fill device.
PTT-N/REQ-N
AT/FILL INFO
FILL l/A
PTT-N is switch separated from REQ-N and routed to the ICOM control
module. REQ-N is used to request fill data. The fill device or the fill
routing module may request fill data.
The audio transmit signal is switch separated in the ICOM data l/O
module. FILL INFO is the fill data passed to and from the fill routing
module.
This is the signal used to check the fill data into and out of the fill routing
module. The presence of a fill device is detected on this line when the fill
device -6.75 V dc signal level is present.
MUX OVRD
(Multiplex Override) This signal is used to place the COMSEC module
under the control of a fill device.
All signals from the fill device pass through level shifting circuits to raise their levels. The fill device uses signals
at 0 V and –6.75 V levels. The fill routing module signal levels are at 0 V and 5.5 V.
The fill routing module’s on board processor controls all signal routing and switching. Commands for operation
are sent to the fill routing module from the control module over the control module out (CM OUT) line, which is an
asynchronous serial communications link.
When the fill routing module detects COMSEC variable fill data, it
routes the data to the COMSEC module and controls the interface with the COMSEC module. When the fill
routing module detects fill data for the ECCM module, it signals a fill input on the FILL DETECT-P line. The fill data
is sent over the asynchronous serial link FR OUT to the control module and then is stored in the ECCM module.
2-19. REMOTE CONTROL OPERATION.
When the RT FCTN switch is set to REM, it can be controlled by a remote control unit. There are two remote
control modes. One mode provides for complete remote control of all front panel functions. It is called the
2-WIRE mode. It allows remote input/output of audio and data signals.
The other mode is called the 6-WIRE
mode. Remote control is limited to RT MODE, RF, CHAN, COMSEC mode, and COMSEC variable. The audio and
data signals are input and output at the RT. The control-monitor uses this mode. When the remote control unit
establishes contact with the RT, it identifies which mode the RT is to use.
The two modules that provide the remote control capability are the two-wire interface (1A6) and the remote l/O
module (1A2). See figure FO-10. The link between the RT and the remote control unit is the 2 WIRE l/O and 2
WIRE I/O RTN lines. Control signals are FSK modulated onto a 2880-Hz carrier. Audio and data signals are
modulated onto a 40-kHz carrier (2-wire mode only).
The two-wire interface sends and receives signals on the 2-WIRE l/O lines. When receiving, it separates the two
carriers. The control information is routed to the remote l/O module. The audio/data information is routed to the
switching module. The remote l/O module decodes the control information and routes it to the control module.
During remote operation, the control module executes instructions from the remote l/O module, not the front
panel. When sending data to the remote control unit, the above process is reversed.
The remote control unit can turn off the RT. The two-wire interface puts 6 V dc on the PS ON-N line to disable the
power supply outputs. The two-wire interface will draw power from the RT dc power input that is routed through
the front panel display board.
2-22
