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 called endpoint.
TEST TRANSFER TO DATA
Perform this test at each voice terminal with a DATA button,
1.
2.
3.
4.
5.
6.
Determine which data terminal or personal computer (PC) is
associated with the DATA button being tested. Be sure the terminal
or PC is turned on.
Go off-hook at the voice terminal.
Dial the DDC of another data terminal
terminal or PC is turned on and idle).or host computer (be sure the
When you hear answer tone, press the DATA button and hang up.
A call is now established between the associated data terminal and
the called terminal.Verify connection by sending a message or
logging in at the called end-point.
Hit  twice within 1 second at one of the data terminals to
disconnect the call.
3-11 
						

							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 CO trunk access code,
and dial the number of a CO trunk that receives night service
coverage.
Verify that the alerting device sounds.
At another voice terminal, go off-hook
access code.and dial the night service
The alerting device ringing should stop.
The call should be picked up.
Verify transmission.
At both voice terminals, go on-hook.
Repeat Steps 2 through 6 for each night service trunk.
At the attendant console, press the Night Service button again and
verify that the Night Service LED goes dark.
3-12 
						

							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 PAGING INTERFACE
Place a test call to each paging zone to verify that paging equipment can be
accessed.
Note:
1.
2.
3.
4.
At
orIf testing ZoneMate 9 (used with PagePac 20), get an
acknowledge tone. Then dial the zone code, and make an
announcement.any working voice terminal, go off-hook and dial the access code
PDC for a particular zone.
You may hear a confirmation tone.
Make an announcement into the handset.
— You should hear the announcement
At the calling voice terminal, go on-hook.from the loudspeaker(s).
Repeat Steps 1 through 3 for all paging zones provided.
3-13 
						

							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 voice terminal, go on-hook.
3-14 
						

							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 an emergency transfer terminal.
You should hear dial tone.
Dial a incoming trunk wired for emergency service.
You should hear a ringback
ringing at the called station.
may be to the calling station
At the called station, go off-hook andtone at the calling terminal and
If a busy tone is heard, the call
verify transmission.
At both emergency transfer stations, go on-hook.
Repeat Steps 2 through 5 for each emergency transfer station,
including the ones you have just rung, to ensure that you can place
as well as receive a call from each.
At Cabinet 1, turn power on using the rocker switch on the back, or
replace the modular connection into the ETU.
3-15 
						

							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 system
(for example, you dialed *O5 and your system does not have
a TN748 CP). Try again.
If you hear dial tone after 1 to 3 seconds of silence, proceed
with this test.
DiaI the digits 1234567890 *#.
Repeat
You should hear a dual-tone, multifrequency (DTMF) signal
as each key is pressed.
You will hear dial tone after entering the “#“ if the test
passes.
the test for each touch-tone receiver.
3-16 
						

							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 is normally a separately replaceable
unit. Examples include circuit packs (CPs), power supplies, fan assemblies,
the Digital Tape Unit, AC Power Distribution Unit, voice terminals, lines, and
trunks.
l System-Detected Errors
l User-Reported Troubles.
For system-detected errors, a light-emitting diode (LED) on the attendant
console automatically lights if the error qualifies as an “alarm. ” This is a
serious error. Most alarms are also indicated by LEDs on system CPs.
User-reported troubles usually result from service problems at individual
voice and data terminals and are often related to alarmed conditions.
Error records and alarms are retired either automatically or manually. After a
trouble or error has been cleared, the system retests the previously faulty
area within a variable time interval. When the error is no longer detected, the
error message and the alarm, if applicable, are retired. By entering
commands at the SAT, maintenance personnel can retire error records and
alarms manually after a problem has been fixed. Also, error records can be
accessed and listed, and some alarms can be removed through the SAT.
However, certain alarms must be cleared manually. After the error messages
have been removed from the error tables, the Attendant Alarm LED (and red
CP LEDs) will go dark unless the trouble recurs.
Note:Information contained in this part applies to the AT&T
System 25 RI VI, R1V2, R2V1 and R3V1. However, in all
cases exceptin the description of CP LEDs, the
CPU/Memory CP (ZTN129 [R2V1] or ZTN130 [R3]) is
referenced rather than the Call Processor CP and Memory
CP used in RIV1 and R1V2.
4-1 
						

							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)
Administration terminal (TI 703KSR or equivalent),
(Comcode 404079436).with 355A adapter
4-2 
						

							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. Damage to integrated circuits caused by
electrostatic discharge may not be immediately apparent.
Caution:The wrist grounding strap must
cabinet location other than the
front-cover retainer screw. The
must not be attached to a CP.not be clipped to any
grounding block or a
wrist grounding strap
4-3 
						

							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 problems,
particularly when the problem has not caused an alarm or when alarms
cannot be retired by replacing faulty units.
The errors are listed in the error tables by time of occurrence. Resolved and
unresolved errors are listed, thus providing a profile of the past and current
state of the system.
Error message explanations are provided under “Error
Messages” in this section.
Emergency Transfer
System 25 has emergency transfer capability in case of total system outage.
The Emergency Transfer Unit (ETU) connects preassigned single-line voice
terminals directly to the CO, bypassing the System 25. Emergency transfer is
invoked by loss of ac power or by any failure of the system that prevents it
from processing calls.
Circuit Pack LEDs
During the various states of operation (start-up testing, normal operation, and
failure), CP
Note:LEDs appear as follows:
The first two listings, Memory and Call Processor, apply only
to Release 1.The CPU/Memory circuit pack applies to
Release 2 and Release 3.