Section 365–262–205
10
stream via the XDATA lead, indicating a busy condition on the channel circuit. An on-hook condition (open)
causes a logic 0 state to be transmitted with the outgoing bit stream and indicates a channel idle condition. On
the 3652–62, the M2-LEAD DETECTOR will cause a logic 1 to be transmitted on the B highway for a ground con-
dition on the M2-lead, and a logic 0 to be transmitted for an open on the M2-lead.
4.3.7.
PLR Signaling (Receive)
The information received from the carrier facility appears on the RDATA lead of the PLR channel unit. A busy
condition (logic 1 state on A signaling highway) detected by the DECODER circuit will cause the E RELAY to op-
erate, the BUSY LED to illuminate, and the off-hook (-battery) signal to be applied to the M-lead of the PLR chan-
nel unit. An idle condition (logic 0 state on A signaling highway) detected by the DECODER circuit will cause the
E RELAY to release, the BUSY LED to extinguish, and the on-hook (ground or open) signal to be applied to the
M-lead of the PLR channel unit. On the 3652–62, when a logic 1 is detected on the B signaling highway, the DE-
CODER will cause the E2 RELAY to operate, applying a -battery condition on the E2-lead. When a logic 0 is de-
tected, the E2-RELAY does not operate, applying a ground or open on the E2-lead.
4.4
NORM/BUSY Switch
In the NORM position, the NORM/BUSY switch provides continuity between the E&M leads and the signaling in-
terface circuitry within the 4W E&M/PLR. In the BUSY position, this switch disconnects the M-lead from the
signaling circuitry, sends an off–hook signal to the opposite end of the carrier facility, illuminates the BUSY LED,
and provides an output signal on the Make Busy Indicator (MBI) lead to light the BUSY LED on the Alarm Logic
Unit (ALU) as a reminder that a channel unit within the digroup has been manually busied.
4.5
Trunk Processing During a Carrier Failure
When an alarm condition is detected, the ALU sends an output signal to the Carrier Group Alarm Immediate
(CGAI) lead on the 4W E&M/PLR. After 2.5 seconds, the ALU sends a signal on the Carrier Group Alarm
Delayed (CGAD) lead. These signals control the state of the E-lead sent toward the trunk circuit during a carrier
failure. One of three trunk processing modes can be selected: E-lead to transmit an idle state then change to a
busy state 2.5 seconds later; E-lead to transmit a busy state; or the E-lead to transmit an idle state. On the
3652–62, one of the three trunk processing modes also occurs on the E2-lead.
Note:
When the channel unit is optioned for tandem mode, the E-lead and M-lead are reversed.
The Trunk Processing (TP) relay (3652–68 only) provides a set of dry contacts between pins 2 and 6 (1-lead and
2-lead) of the module connector. During a carrier failure, the TP relay is activated by a signal on the Carrier Group
Alarm Wink (CGAW) lead that causes the contacts to close, wink open for 70 milliseconds after 2.5 seconds, then
close again. The 2-lead can be grounded (optionable) to provide a switched ground output on the 1-lead.
When the channel unit is removed from its mounting position, the 1-lead/E2-lead (Pin 2) and the E-lead (Pin 4)
are grounded through a shorting contact in the card connector, and an all-ones quiet busy code is transmitted to
the far-end terminal.
5.
MOUNTING
The 3652–62/68 mounts in one channel unit slot of a 360/363 D4 terminal. The 3652/68 is equipped with an in-
sert/eject lever in the form of a hinged front panel which ensures a positive connection of the channel unit’s card-
edge connector to the backplane connector when the unit is installed. The insert/eject lever also facilitates remov-
al of the unit.
Installation and removal of modules should be done with care. Do not force a module into place. If
excessive resistance is encountered while installing a module, remove the module and check the card
guide and connector to verify proper alignment and the absence of foreign material.
CAUTION
Align the channel unit with the appropriate card-guided slot of the terminal. Slide the unit into the slot with the
front panel in a horizontal (up) position. When the top portion of the hinged front panel is under the front lip of the
terminal, push down on the front panel until it is in the vertical (down) position. The channel unit’s card-edge con-
nector will begin to make contact with the inner portion of the backplane connector. Continue applying light pres-
sure onto the bottom edge of the front panel until the unit snaps into place.
