TM 11-5821-333-30
4-5. CONTROL SIGNALS
The dra has many control functions that determine how signals preprocessed and routed. The data processor
module handles the major portion of control for the dra. It makes decisions which instruct the other modules in
their operating modes: voice/FSK, transmit/receive, plain-text/cipher-text, analog/digital.
The following chart is a list of control signals and a list of their functions. Figure FO-14 shows routing of the
signals.
SIGNAL
DESCRIPTION
AUDIO MOD PTT
Logic 0 = Transmit
Logic 1 = Otherwise
CGC
Gnd = Cipher-text selected
Open = Plain-text selected
DATA l/O ENBL
Logic 1 = Valid digital mode
Logic 0 = Otherwise
In rcv mode, goes to logic 0
until inverted code is detected.
DATA 1/0 ENBL OUT
DDMC
DELAYED PTT
DIG DATA CLK IN
DIG DATA CLK OUT
DIG SQUELCH
RCV CLK IN
RCV CLK OUT
RED DDMC
SQ CONT
SQUELCH
VOICE/FSK SEL
Logic 1 = Valid plain-text digital mode
Logic 0 = Otherwise
Gnd = Digital data mode
Open = Otherwise
Logic 1 = Plain-text xmt mode
Logic 0 = Rev, standby, or cipher text mode
Delayed approximately 2 msec on release.
16 kHz clock from KY-58
16 kHz clock to digital data device
Logic 1 = Digital signal received in plain-text
or KY-58 active in cipher-text
Logic 0 = Otherwise
16 kHz clock; regenerated by bit sync in
plain text: from KY-58 in cipher text
Buffered version of RCV CLK IN; during self-
test clock is generated on FSK detector module
Logic 0 = Digital data mode
Logic 1 = Otherwise
Logic 0 = KY-58 active (digital signal received
or encrypting transmit signal)
Open = Otherwise
Buffered version of DIG SQUELCH
Logic 1 = FSK receive, FSK test, or self-test
Logic 0 = Voice receive
4 -4
