TM 11-5805-424-15/NAVSHIPS 0967-220-9013/TO 31W2-2G-41
b. Talk-Request Detection.
from IN-12 ungenerated by bistable FFA-1 through the
hidden OR gate to the risetime and falltime shaper.
Unregenerated output from amplifier IN-12 is also
(1) Under normal data operation, amplifier IN-16
applied to AND gate GAS-4 for use with the no-
is held on by the no-alarm output (-15 volts) of amplifier
transition receive alarm circuits (para 5-24).
IN-10 in the receive input and carrier alarm module.
Both timers are inactive, and bistable FFB-1 is in a set
state with a high positive level output at its 1-output line,
5-23. Order-wire Circuit Operation (fig. 8-5)
and TALK REQUEST indicator lamp DS3 is extingished.
a. Talk-Request Generation
(2) When a 1.5-second talk-request signal is
received by the receive input and carrier alarm module,
(1) When TALK REQUEST switch 1A1S3 is
amplifier IN-10 assumes the alarm condition and
depressed, a ground is applied through the hidden OR
provides a High Positive Level at its output (para 5-24).
gate to amplifier IN-24 Amplifier IN-24 applies a ground
This High Positive Level cuts off amplifier IN-16. which
output to trigger bistable FFF-1 and (through OR gate
activates initial timer Q2, Q3, Q4. The negative output
GOA-6) to bistable FFE-1. A remote talk-request signal
of amplifier IN-16 inhibits AND gate GAI-3 which
(ground may also be used to initiate the talk request. (If
prevents receive data signals from being applied to the
this application is desired, terminals 1, 2, and 3 are
receive data output terminals. The initial timer times out
connected together).
a delay of approximately 1 second (adjustable by
DELAY resistor 1A1R9). After the delay the positive
(a) With FFF-1 cleared the positive output
output of initial timer Q2. Q3, Q4, is applied to the
from its 0-output line is applied to OR gate GOA-2 in the
window timer Q5, Q6, Q7, (4 below) through resistor
transmit output and carrier alarm module (inhibiting the
R11 to amplifier IN-17.
transmit carrier alarm circuits) and to OR gate GOA-1 in
the input interface and common alarm module
(3) Positive output from initial timer Q2, Q3, Q4 is
(inhibiting the no-transition-send alarm circuitry).
inverted by amplifier IN-17, applying a negative input to
NAND gate GAD-3. The positive talk-request signal
(b) With FFE-1 cleared the positive output
(input to amplifier IN-161 maintains NAND gate GAD-3
from its O-output line inhibits bistable FFC-8 in the
in an inhibited condition, which provides a positive
transmit 64 divider module, thus inhibiting the transmit
output that is inverted by amplifier IN-18 to a negative
carrier. The negative output at the 1-output line of FFE-
level that has no effect on bistable FFB1. However,
1 activates the 1.5-second delay; after 1.5 seconds,
when the talk-request signal is removed (after 1.5
FFE-1 is set by the 1.5-second delay. The positive
seconds, both NAND gate GAD-3 inputs are negative.
output at the l-output line of FFE-1 deactivates the
providing a negative output that clear bistable FFB-1
1.5second delay, and removal of the positive output
when inverted to a positive signal by amplifier IN-18.
from the O-output line of FFE-1 unblocks the transmit
With bistable FFB-1 cleared a negative output is present
carrier. Thus, the carrier signal is interrupted for a
on its 1-output line, and a positive output is present on
period of exactly 1.5 seconds; this is interpreted at the
its 0-output line. These outputs serve in automatic
other site as a talk request signal ( b below). The
switching of timing bistable FFA-1 in the receive data
transmit carrier alarm remains inhibited during the entire
output module (para 5-221. The negative output at the
talk request mode of operation.
1-output line of FFB-1 inverted by amplifier IN19,
provides a ground to light TALK REQUEST indicator
(2) When the order-wire mode of operation is no
lamp DS3. The positive level at the 0-output line
longer required, TALK REQUEST RESET pushbutton
inhibits OR gate GOC-1 in the receive input and carrier
1A1S4 is depressed, applying + 15 volts to bistable
alarm module, and OR gate GOA-3 in the receive data
FFF-1, setting the bistable, and removing the positive
output
inhibit level from OR gate GOA-2 (transmit carrier alarm
circuits) and GOA-1 (NO-TRANSITIONSEND-ALARM
circuits).
Change 5
5-25
