SECTION
5 18-411-1 00
The 487 A KTU also provides an LED for call
supervision and dial pulse detection.
E.
488A KTU-Line Interface Circuit
2.18
The 488A KTU provides limited access to
the CO/PBX lines.
One 488A KTU is
required for each two lines to perform the following
functions:
•
Isolate the 6B KTS from CO/PBX line
potentials
•
Detect and acknowledge supervisory signals
from the line
•
Transfer control information on the A and
L leads from the CO/PBX line circuit to
the controller circuit.
The 488A KTUs are installed in j acks Jl9, J21,
J23, and J25, as required.
These KTUs occupy
double-width jack positions.
F.
489A
KTU-TOUCH-TONE Decoder Circuit
2.19
The 489A KTU performs the function of
interpreting the tone address signals from
the station dial. The frequency detectors of the
489A KTU convert the information to bits which
are processed by the controller circuit.
The
controller resets the TOUCH-TONE receiver after
each dialed digit in preparation for subsequent
dialing. The optional 489A KTU is installed in Jl.
184C 1
BACKBOARD
2.20
The optional 184Cl backboard consists of a
yellow metal backboard equipped with a
14A2-125 terminal block, providing terminations
for 8 CO/PBX lines and 20 stations (Fig. 2). Space
is provided for the addition of two more terminal
blocks which must be separately ordered. Addition
of the second block adds capacity for 25 more
stations.
Addition of the third block adds the
final stations.
The 184Cl backboard offers a
convenient method of grouping the 6B KTS
terminations, but is not required if the yellow field
of
a
centralized key system installation can be
utilized.
2.21
The 14A2-125 terminal blocks used with the
184Cl backboard consist of a 66-type
connecting block wired to five microribbon plugs.
Page
8
The plugs accept A25B connector cables to provide
connections between the backboard and the 572Al
KSU.
Fig. 2 shows the layout of the 184Cl
backboard and the plugs to be used in connecting
to the 572Al KSU. All station connections and
the A and lamp leads from the station side of the
line circuits are made on the terminal blocks of
the 184Cl backboard. Tip and ring of the CO/PBX
lines (from ahead of the line circuit) are fed through
a separate cable to P13 on the KSU.
3.
INSTALLATION
ORDERING GUIDE
Basic System
•
Unit, Key Service, 572Al-one required per
system.
Where desired, the 572Al KSU
can be mounted in a 16C apparatus mounting
with a 117C cover. These items must be
separately ordered.
•
Backboard, 1 84Cl-equipped with one
14A2-125 terminal block.
Order one per
system when yellow field of centralized
system is not used. Has terminations for
8 CO/PBX lines (A and L leads) and
20
stations.
•
Block, Terminal, 14A2-125-order one to
add additional 25 stations to 184Cl backboard.
Order second block to extend number of
stations over 45.
•
Cable, Connector, A25B-order as required
for connections between 572Al KSU and
184Cl backboard and yellow field. Cables
used with 1 84Cl backboard must be
double-ended.
•
Unit, Key Telephone, 484A (station
circuit)-order as required. Each KTU has
circuitry for 4 stations.
•
Unit, Key Telephone, 485A (controller
circuit)-order one per system.
•
U nit, Key Telephone, 486A (service
circuit)-order one per system.
e
Unit, Key Telephone, 487A (battery feed
circuit)-order one per system.
KTU
B S P S18-411·100·i01_1978-08-08.jpg Scanned b y Frank Harrell, (Cowboy Frank) Castle Rock, Colorado Oct 1 5 , 2 0 1 2 20:57:08
