Meridian America 71 ユーザーズマニュアル
PRACTICE 553 -2201-184
2. DESCRIPTION
2.01 The SL-1 and console line circuit packs each contain eight line
circuits (see Fig.
The SL-1 line pack can use all eight circuits,
each circuit interfacing to an SL-1 set. The console line pack uses pairs
of line circuits to interface to attendant consoles: one pair may be used
from the upper four circuits and one pair from the lower four to
interface to two consoles.
from the upper four circuits and one pair from the lower four to
interface to two consoles.
Note:
Line circuits on the SL-1 line pack are automatically
powered up during signaling and transmission. The connected
circuit pairs on the console line pack are continuously powered on.
circuit pairs on the console line pack are continuously powered on.
2.02 For SL-1 set connections. one pair of wires is used
transmission and a second pair for signaling (see Fig. 2-2). For
attendant console connections, two pairs of wires are used for
transmission connections and two pairs for signaling connections. These
transmission and a second pair for signaling (see Fig. 2-2). For
attendant console connections, two pairs of wires are used for
transmission connections and two pairs for signaling connections. These
Lions:
(a) terminate the loop tip and ring conductors with a balanced
600-ohm termination:
provide
V power, phantomed over the transmission and
signaling pairs, to the set or console terminals:
provide a measure of isolation of foreign potentials on the loop
from portions of the transmission and signaling circuitry;
convert from the 2-wire transmission path of the loop to a 4-wire
transmission path:
provide analog-to-digital and digital-to-analog conversion
transmission signals.
2.03 The circuit pack includes two common multiplexing circuits to:
(a) interface the individual line circuits with the peripheral bus
signaling channel:
retime digital signals received from the peripheral bus;
decode address information received from the peripheral bus and
enable individual line circuits during selected time slots.
2.04 The information and signaling relevant to the SL-1 set or console
passes through the line circuit pack and is multiplexed with information
from other circuit packs. A multiplex loop connects the input and
output of up to two Peripheral Equipment
passes through the line circuit pack and is multiplexed with information
from other circuit packs. A multiplex loop connects the input and
output of up to two Peripheral Equipment
shelves to the Common
Equipment
where switching takes place (see Fig. 2-2 and 2-3).
PHYSICAL
2.05 The line circuits and common circuitry of the pack are mounted
DESCRIPTION
on a 12.5 in
by 10 in
printed circuit board. The
front of the pack is equipped with two pack extractors and a Light
Emitting Diode
Emitting Diode
The rear of the pack is equipped with a
connector capable of accepting 80 pins. Ten of these circuit packs may
be mounted in one PE shelf but not to exceed 50% of the packs in a
cabinet.
be mounted in one PE shelf but not to exceed 50% of the packs in a
cabinet.
Page 2-l
3
Pages
Revised, 85 06