TM 11-5805-424-15/NAVSHIPS 0967-220-9013/TO 31W2-2G-41
d. No-Transition Receive Alarm. The no-transition
applied from ALARM switch 1AIS6 (DISABLE position),
or from bistable FFF-I in the talk-request generator
receive alarm is activated when no data transitions are
module when orderwire circuit operation is activated
being applied to the receive output terminals.
(para 5-231.
(1) Normally, with no alarm condition, signal
c. Loss-of-Transmit-Carrier Alarm. The loss-of-
transitions are applied through AND gate GAI-3 and
through AND gates GAS-3 and GAS4 so that each
transmit-carrier alarm will be activated if the transmit-
signal transition is applied as a positive pulse to the
carrier output is interrupted for 2 seconds or longer.
delay driver. As long as positive pulses are applied to
the delay driver (time between transitions is not greater
(1) When the carrier signal is interrupted, the
than 200 milliseconds), the delay driver remains
output of the transmit filter to OUTPUT LEVEL ADJ
inactive, providing a negative output to maintain 5-
resistor 1A1R6 (transmit output and carrier alarm
second delay Q6 through Q11 deactivated.
The
module) is removed. With no signal applied through
resultant negative output form 5-second delay Q6
XMIT CARRIER ALARM THRESHOLD resistor 1AIR14
through Q11 is applied to inhibit OR gate GOB-1, in the
(which presets the minimum signal level requirements
input interface and common alarm module, keeping
before an alarm condition is detected), level threshold
ALARM indicator lamp 1A1DS2 in the off condition (b
Q4, Q5 in the transmit output and carrier alarm module
does not have an output. This drop in signal level is
(1) above).
interpreted by IAM) Detector Q6-Q8 as an alarm
condition. With no input to IAMI Detector Q6-Q8, a
(2) If data transitions occur at intervals greater
positive output is applied to activate 2-second delay Q9-
than 200 milliseconds but less than 5 seconds apart, the
Q 11.
delay driver provides a positive input to activate the 5-
second delay (after 200 milliseconds).
The next
(a) If the carrier level is restored before 2
transition resets the delay driver; consequently, the
5second delay is reset, producing no change in the
seconds have elapsed, level threshold Q4, Q5 provides
output.
an output dc level to reset (AM) Detector Q6-Q8 and 2-
second delay Q9-QII before any change in the output
(3) If no transition is produced after 5 seconds, 5-
can occur.
second delay Q6, QII times out and provides a high-
level output (ground) that enables OR gate GOB-1
(b) If the carrier level remains below the
(input interface and common alarm module), lighting
predetermined level (as determined by XMIT CARRIER
ALARM indicator lamp 1A1DS2 (b(3 above). The
ALARM THRESHOLD resistor 1A1R14), 2-second delay
ground output from 5-second delay Q6, Q11 turns on
Q9-Q 11 times out and provides a high-level output to
amplifier IN-13, providing a ground output that is applied
OR gate GOB-1, which lights ALARM indicator lamp
to the NO TRANSITION ALARM REC output terminal,
1AiDS2 (b(3) above). The output of the 2-SEC delay
to activate an external no-transition receive alarm.
Q9-QII is also inverted by amplifier IN-8 and applied as
a low-level (ground, in this case) alarm signal to the
(4) The no-transition receive alarm may be
LOSS OF XMTR CARRIER ALARM output terminal, to
deactivated by applying a high level (+ 6 volts) through
activate an external loss-to-transmit-carrier alarm. The
OR gate GOA-3 to the delay driver, keeping the delay
loss-of-transmit-carrier alarm can be deactivated by
driver deactivated, and holding ALARM indicator lamp
applying a high-level input (+ 6 volts) through OR gate
1A1DS2 off ((1 above. The high-level input may be
GOA-2, which applies a steady positive level to the
applied from ALARM switch lAlS6 (DISABLE position l
1AM1 Detector and keeps 2-second delay Q9-Q11
or from bistable FFB-1 (talk-request detection module)
deactivated. The positive input to OR gate GOA-2 may
when a talk-request signal has been detected, signifying
be applied from ALARM switch 1A1S6 (DISABLE
the order-wire circuit mode of operation (para 5-23).
position( or from bistable FFF-1 ion the talk request
generator module when order-wire circuit operation is
e. Loss-of-Receive-Carrier Alarm. This alarm is
activated (para 5-23).
activated when the input fsk signals applied to the
receive input terminals are interrupted or fall below a
predetermined level, for 2 seconds or longer.
Change 3
5-27
