NAVELEX EE181-AA-OMI-090/E121 SA-1954
Table 2-1. Operator Controls and Indicators
Provides an alarm signal output when actuated.
After an alarm has been responded
to, notify appropriate direct sup-
port maintenance personnel to
reset the LAS to a no-alarm
LED comes on when alarm is actuated;
goes off when alarm switch is reset.
Section II. THEORY OF OPERATION
age is applied to one side of the latching relay. With the
2-3. FUNCTIONAL DESCRIPTION.
latching relay operating and latched, the closed latching
relay contacts provide a continuous signal path and
a. The LAS permits authorized personnel to manually
return path through an LED. The indicator light (LED),
activate an alarm signal to the J-SIIDS Control Unit
on the front of the LAS comes on red and remains on as
when the security of an area is threatened. The LAS
long as the duress alarm signal is present. The indicator
chassis cover contains a tamper switch that also
light goes out when the reset switch is pressed and the
activates an alarm signal when the cover is
LAS returns to the no-alarm state.
removed from the housing by inch (0.635 cm) or
more. See figure 2-2 for a simplified functional
(2) Duress alarm reset. When the duress alarm
block diagram of the LAS.
switch is actuated, the alarm signal and the alarm
b. The LAS has four operational modes as follows:
indicator light will remain on until the reset switch is
duress alarm, duress alarm reset, tam-per alarm,
pressed. When the reset switch is pressed, voltage is
and no alarm.
applied to the other side of the latching relay which
restores the relay contacts to the no-alarm condition.
(1) Duress alarm. When an operator actuates the
duress alarm switch, the low impedance across TB1-1
(3) Tamper alarm. When the cover is moved from
and TB1-2 is changed to a high impedance which is
the chassis by 1/4 inch (0.635 cm) or more, a tamper
used as the duress alarm signal output. When the
alarm switch on the inside of the cover activates a
duress alarm switch contacts open, volt-
tamper alarm signal. When the cover