TM 55-1510-220-10
Figure 3-8. Voice Security Control Panel (TSEC/KY-75)
b.
Controls/Indicators and Functions.
(1)
RMT-LOCAL-SIG
CLR
switch. Selects
operating mode.
(a)
RMT. In this position the PLAIN/
CIPHER selection is controlled by input outside KY-75
control panel.
(b)
LOCAL. In this position, transmit
mode is controlled by PLAIN/ CIPHER switch.
(c)
SIG CLR. In this position, if a fill
device is connected to the FILL connector, the alarms will be
set, and the selected fill register will be cleared. Upon release
of the switch (it is spring loaded to the LOCAL position) the
TSEC/ KY-75 will request a fill variable from the fill device.
If a fill device is not connected, a steady tone signal will be
transmitted to all other units within the net, indicating a
desire to establish communications on that link.
(2)
PLAIN/CIPHER switch. Selects plain or
cipher mode.
(a)
PLAIN. The TSEC/KY-75 system will
receive cipher and plain signals and will transmit plain.
(b)
CIPHER.
Permits
ciphered
communication.
(3)
P WR/FILL switch. Controls set power and
fill positions.
(a)
OFF/ZEROIZE. All power is removed
from the TSEC/KY-75 system and all fill registers are
zeroized. (To enter this position, the switch must be pulled
out and rotated counterclockwise.)
(b)
1, 2, 3 fill positions. These positions
are used to select the fill register of the TSEC/ KY-75 system
to be used during transmission and reception of ciphered
messages.
(4)
ALARM indicator. This indicator illuminates
when a fill error, randomizer, or battery failure occurs. The
indicator includes a press-to-test feature.
(5)
PLAIN indicator. This indicator illuminates
when the PLAIN/CIPHER switch is set to the PLAIN
position. The indicator includes a press-to-test feature.
(6)
CIPHER indicator. This indicator illuminates
when the PLAIN/CIPHER switch is set to the CIPHER
position. The indicator includes a press-to-test feature.
(7)
SIG/CIPHER RCV indicator. This indicator
(blue) blinks continuously when the TSEC/KY-75 system is
receiving ciphered text. The indicator includes a press-to-test
feature.
Change 2
3-17
