ATT System 25 Installation And Maintenance Manual

SYSTEM TESTS
MAKE POOLED MODEM TEST CALL
Skip this test if the system does not include a TN758 Pooled Modem CP.
This test involves placing a data call from a data terminal connected through
an ADU from a data terminal or personal computer connected via a modem
(the modem may be part of a terminal connected to System 25 or off
premises).Place the call following the dialing procedure required by the
modem. When you hear answer
now be able to communicate with
tone, transfer the call to data. You should
the...

SYSTEM TESTS
TEST EXTERNAL ALERT (NIGHT SERVICE)
Place a
sounds
alerting
alerting
1.
2.
3.
4.
5.
6.
7.
8.
test call to the attendant console to verify that the alerting device
when
device
device
At thethe attendant console is in the Night Service mode. If an
has not yet been installed, connect a spare voice terminal or
to the modular jack reserved for the alerting device.
attendant console, press the Night Service button.
The Night Service LED lights steadily.
At any voice terminal, go off-hook. Dial the...

SYSTEM TESTS
TEST DICTATION SYSTEM ACCESS
Place a call to verify that dictation equipment can be accessed. If dictation
equipment has not been installed, this feature cannot be tested.
1.
2.
3.
4.
5.
Use a working voice terminal as the test terminal, and go off-hook.
Dial the access code or PDC, and the number associated with the
dictation equipment.
Verify that ready or talkdown tone is transmitted.
Transmission in
and play it back
Go on-hook.
both direction should be tested. Make a recording
TEST...

SYSTEM
TEST
TESTS
MUSIC-ON-HOLD
Verify that music is provided to outside callers placed on hold. (Inside callers
do not receive Music-on-Hold [MOH].)
1.
2.
3.
4.
5.
At any working voice terminal, go off-hook. Dial the CO trunk access
code and the system’s listed directory number, or if DID, dial any
station.
At the called
At the called
Thestation, answer the incoming call.
station, press HOLD.line button’s green LED should flash.
Verify that music is heard at the calling voice terminal.
At the calling...

SYSTEM TESTS
TEST EMERGENCY TRANSFER
Place the system in emergency transfer mode by turning power off (or
remove the modular connector from the ETU). Place an outside call from
each emergency transfer station.
1.
2.
3.
4.
5.
6.
7.
8.
At Cabinet 1, turn the power off using the rocker switch on the back
or remove the modular connector from the ETU.
For ground start trunks, at an emergency transfer voice terminal, go
off-hook. Press the ground start key, if so equipped.
For loop start trunks, go off hook at...

SYSTEM TESTS
TEST TOUCH-TONE RECEIVERS
1.
2.
3.
At a single-line voice terminal, go off-hook. Dial *3 and the 2-digit
number (01 through 12) of the touch-tone receiver to be tested.
Receivers 01 through 04 are on the ZTN85 or ZTN131 (R3) CP.
Receivers 05 through 12 are only present if your system has two
TN748 CPs (05 through 08 receivers on one, and 09 through 12
receivers on the other).
You will hear busy tone if the receiver is in use, reorder tone
if you misdialed or addressed a receiver not in your...

MAINTENANCE
MAINTENANCE
The primary maintenance objective is to detect, report, and clear troubles as
quickly as possible with minimum disruption to normal service. Periodic
system self-tests, automatic software diagnostic programs, and fault
detection hardware are several of the maintenance tools used to achieve this
objective. Most troubles in System 25 can be isolated to a replaceable unit.
The System 25 hardware is maintained as a group of independent units (that
is, maintenance objects). Each object...

MAINTENANCE
EQUIPMENT NEEDED
The
any
maintenance technician
System 25 service call:should take the following tools and equipment on
EIA breakout box
Digital voltmeter (KS-20599 or equivalent)
11 O/66-type punchdown tool (AT 8762D or equivalent)
Dracon TS21 or equivalent touch-tone test set
Assorted flat-head screwdrivers
Assorted Phillips-head screwdrivers
Long-nosed pliers
Regular pliers
Wrist grounding strap
Model DC4 Digital Tape Unit, with 355A adapter and a D8W cord
(Comcode 404079429)...

MAINTENANCE
Precautions
Electromagnetic fields radiating from the system cabinets may generate noise
in other communications equipment. The technician must be sure that all
cabinet panels and covers
are securely in place after performing
maintenance.
Caution:Electrostatic discharge can destroy or severely damage
integrated circuits on CPs.
The maintenance technician MUST ALWAYS WEAR A WRIST GROUNDING
STRAP when handling CPs.The cord must be attached to the grounding
block at the back of the cabinet....

MAINTENANCE
GENERALMAINTENANCE INFORMATION
System Errors and Alarms
During periodic testing, a maintenance audit could detect a system error that
automatically generates an error record.Depending on severity, the error
record is stored in one of following three tables in the Error Log:
lPermanent System Alarms
l Transient System Errors
l Most Recent System Errors.
The three error tables can be displayed at the System Administration
Terminal (SAT). The error tables are used to diagnose and analyze...