ATT System 25 Reference Manual

							HARDWARE DESCRIPTION
Trunk Port Circuit Packs
l TN753 DID Trunk
Provides eight ports for immediate-start or wink-start Direct Inward Dialing (DID)
trunks.
l TN760B Tie Trunk
Provides four ports for Type 1 E&M, Type 1 E&M Compatible, or Type 5 Simplex tie
trunks. Operating protocols include automatic, immediate-start, wink-start, or delay
dial. The TN760B contains option switches for supporting the following signaling
formats:
— Type 1 E&M Standard (Unprotected)
— Type 1 E&M Compatible (Unprotected)
— Type 1 E&M Compatible (Protected)
— Type 5 Simplex
l TN763 Auxiliary Trunk
Provides four ports for on-premises auxiliary equipment (paging systems and
dictation systems).
l TN767 DS1 Interface
Provides 24 trunk ports per digital T1 carrier interface. Supported trunks include
automatic tie trunk, delay dial tie, immediate dial tie, wink start tie, ground start
central office trunk type, loop start central office trunk type, direct inward dial trunk,
and off-premises station line.
l ZTN76 Ground Start Trunk
Provides eight ports for Ground Start Central Office (CO), Foreign Exchange (FX), or
Wide Area Telephone Service (WATS) trunks.
l ZTN77 Loop Start Trunk
Provides eight ports for loop-start CO, FX, or WATS trunks.
Refer to Section 9,“Glossary” for Ground Start and Loop Start definitions. Ground Start
trunks are recommended for use where possible.
Trunk specifications are provided in Section 5, “Technical Specifications.”
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							HARDWARE DESCRIPTION
System Resource Circuit Packs
l TN748B and TN748C Tone Detector
Provides four touch-tone receivers; the system can have a maximum of two TN748B
or TN748CS, depending on the number of stations and the conditions in Table 4-C.
One TN748B or TN748C CP must be used in addition to the ZTN131 Service Circuit
in accordance with Table 4-C.
Table 4-C.Tone Detector Requirements
Number of Tone Detector (TN748B or TN748C) CPs
Traffic
(Calls/Hr.)No Account
Codes Used and
no Voice Message
System (VMS)Automated
Attendant
or VMSAutomated
Attendant
and VMS
1100
01
180
011
350
012
420
112
610122
710
12Unsupported
11001
Unsupported   Unsupported
1400
2UnsupportedUnsupported
l TN758 Pooled Modem
Provides two integrated 212-modem compatible conversion resources for switched
connections between analog endpoints (modems), or a digital endpoint and an analog
endpoint. A maximum of two TN758s (four conversion resources) is permitted in
each cabinet.
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							HARDWARE DESCRIPTION
Circuit Pack Compatibility
The following System 75 CPs can be used in System 25, if required:
l The TN742 and TN746B Analog Line circuit packs can be used instead of the ZTN78 Tip
Ring CP. The TN742 and TN746B support bridged stations and out-of-building or Off
Premises Stations (OPS), the ZTN78 does not. The TN746B will only function properly in
R3V3 systems.
l The TN762B Hybrid Line (Version 4 or later) can be used instead of the ZTN79.
l The TN747 CO Trunk can be used instead of the ZTN76 (Ground Start Trunk) or the
ZTN77 (Loop Start Trunk).
Circuit Pack Features
All system CPs have the following features:
l Solid-state circuitry mounted on 7.7 by 14.1-inch printed wiring board (TN-type)
l Color coded faceplate labels identify the CP type and function (White = Control, Purple =
Port or System Resource)
l Individual circuit functions all contained on one CP
l Metal tab for grounding
l Locking tab-type handle provides easy insertion or removal of a CP
l Port CPs can be inserted or removed with power “On” and the system processing calls.
Only the calls utilizing circuits on a removed CP will be affected.
Note: Power must be turned off when replacing the CPU/MEM or Service Circuit.
l Status LEDs
— Port CPs:
Red—“On” several seconds during power up and test, “Off” with test pass. After test
pass, “On” if fault in CP is subsequently detected.
Green—“On” indicates resource available (port is translated).
Yellow—“On” indicates a call in progress. “Off” when not in use.
All LEDs “Off”—CP is not translated.
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							HARDWARE DESCRIPTION
— CPU/MEM CP: Green status LED only. “Off” for several seconds during power up and
test, then lamp flashes to indicate an “OK” state. Steady “Off” or “On” indicates a
problem.
— System Resource CPs:
Service Circuit CP - Similar to port CPs except yellow LED flashes to show system
clock is active and is steadily “On” when a tone receiver is in use. “Off” indicates a
problem.
Modem Pool and Tone Detector CPs - Same as Port CPs.
Terminal Equipment
Terminal equipment is connected to System 25 station (voice or data) ports. It is made up of the
following groups:
l Voice Terminals
— Single-Line
— Multiline (MERLIN
® Communications System sets and MET sets)
— Multiline ATL cordless telephones
l Voice Terminal Adjuncts
l Attendant Consoles
l Asynchronous Data Units (for interface with data terminals).
This subsection provides information on all components in each group or contains references to the
Section where information can be found.
Voice Terminals
System 25 supports a wide range of voice terminals, including industry standard touch-tone single-
line telephone sets, MERLIN System multiline sets, and ATL cordless telephones.
In addition to providing basic telephone service (placing and answering calls), voice terminals can
also be used to activate many system features. The voice terminals supported by System 25 are
listed in Table 4-D and described in individual subsections.
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							HARDWARE DESCRIPTION
Table 4-D.Summary of Voice Terminals
TERMINALCIRCUIT PACK
TYPE *
MODELDESCRIPTIONINTERFACE
420Memory Set with Built-in Speakerphone
500MMRotary Desk SetZTN78
Single-Line500SMRotary Desk Set Compatibleor
Tip Ringwith 4A SpeakerphoneTN742
(Analog)554BMPARotary Wall Set
†2500MMGBBasic Touch-Tone Desk Set
2500MMGTBasic Desk Set with Recall Button
2500DMGCBasic Desk Set with Message Waiting
2500SMBasic Desk Set Compatible
with 4A Speakerphone
2514BMWBasic Desk Set with Headset Jack
2526BMWGWeatherproof Wall Set
2554BMBasic Wall Set
7101ADesk or Wall Set (MD)
7302H01D5-ButtonZTN79
MERLIN Sys.7303H01D10-Button
Multiline7305H01D34-Button (MD)
7300H Series7305H02D34-Button Deluxe
(Hybrid)7305H03BBIS Set (Built-in Speakerphone)
7305H04CBIS Set with Display
7309H01BHFAI Set (Hands-Free-Answer
on Intercom)
7313H01ABIS-10 (10-Button)
7314H01ABIS-22 (22-Button)
7316H01ABIS-34 (34-Button)
7317H01ABIS-34D (34-Button with Display)
MET ‡2991C0510-Button (Desk)TN735
Multiline2991D0510-Button (Wall)
(Hybrid)2993C0410-Button with BIS
7302M12-Button (Desk)
MultilineATL5-Button Cordless TelephoneZTN79
Cordless
Telephone
* System 25 supports several voice terminals that are no longer orderable.
These include MET sets and the 34-button (basic) MERLIN System set.
† The system supports equivalent industry standard touch-tone single-line
sets. Voice terminals connected via the ZTN78 Tip Ring Line CP must have
a REN less than or equal to 1.15 A/B.
‡ The 2991C04 set [with Busy Lamp Field (BLF)] will not operate with
System 25 unless specially modified. The BLF itself will always be inoperable.
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							HARDWARE DESCRIPTION
Single-Line Voice Terminals
Single-line terminals can have only one incoming call ringing when the terminal is idle. The
user at any busy single-line terminal can put an active call on hold and either originate a call
or answer a waiting/camped-on call. Single-line terminals have access to most system
features that do not require operation of programmable buttons.
All voice and control information between single-line terminals and the system digital switch
is transmitted in analog form on tip and ring pairs of wire (one pair per terminal). Port
circuits (ZTN78 Tip Ring Line CP or TN742 Analog Line CP) in the switch provide
analog/digital conversion. Power for terminals is also sent from the switch on the tip and ring
pairs.The pushbutton dials on single-line sets (except for the 500 Series) are touch-tone
pads, which generate Dual Tone Multifrequency (DTMF) signals. The rotary 500 sets
generate dial pulses.
The following subsections provide descriptions and illustrations of the single-line voice
terminals supported by System 25.
500 Series
The Model 500 Series consists of conventional rotary dial telephones. They are
recommended for use as a Power Failure Transfer (PFT) stations if the PFT trunk does not
support touch-tone dialing.A KS 23566,L1 Ground Start button must be used with these
sets if the PFT trunk is ground start. Rotary set users cannot do any procedures that require
pressing the V or # buttons.The following 500 Series sets are supported by System 25;
these sets are similar in appearance to the 2500 sets shown in Figure 4-4 except for their
rotary dials.
l Model 500MM—Basic desk set (PEC 3100-0RD)
l Model 500SM—Desk set with 4A Speakerphone compatibility (PEC 3100-2RD)
l Model 554BMPA—Basic wall set (PEC 3100-0RW).
2500 Series
The following 2500 Series voice terminals have the following components and features:
l Handset
l Touch-Tone Dial
l Ringer Volume Control.
Several 2500 Series voice terminals are shown in Figure 4-4. System 25 supports the
following 2500 Series sets:
l Model 2500DMGC—Desk Set with message waiting indicator and Recall button for
timed switchhook flash (PEC 3178-SYS)
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							HARDWARE DESCRIPTION
l Model 2500MMGB—Basic desk set (PEC 3100-1TD)
l Model 2500MMGT—Basic desk set with Recall button (PEC 3100-TRC)
l Model 2500SM—Basic desk set that can be used with a 4A Speakerphone (PEC
3100-2TD)
l Model 2514BMW—Basic desk set equipped with built-in headset jack
l Model 2554BM—Basic wall-mounted set (PEC 3100-TWR).
Adjuncts: Refer to Table 4-E.
2500MMGB BASIC DESK SET
HANDSET
TOUCH-TONE
TELEPHONE
DIAL
2554BM
BASIC
WALL SET
RINGER
VOLUME
MESSAGE
RECALL
INDICATOR
2500DMGC DESK SET WITH
EXTRA FEATURES
Figure 4-4.
2500 Series Analog Voice Terminals
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							HARDWARE DESCRIPTION
Table 4-E.
2500 Series Voice Terminal Adjuncts
ADJUNCT2500DMGC2500MMGB2500SM2514BMW2554BM
4A SpeakerphoneX
KS 23566,L1 GroundXXXXX
Start Key
Answering Machine
XXXXX
Z3A MessageXXXX
Waiting Indicator (MD)
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							HARDWARE DESCRIPTION
2526BMWG Voice Terminal
This analog terminal (Figure 4-5) consists of a standard touch-tone wall set equipped with a
special faceplate and mounted in a weatherproof housing. The door of the housing can be
fitted with an optional lock.This voice terminal is intended for outdoor use on buildings.
fences, or poles.The 2526BMWG set can be connected for one line or two lines. It is
approximately 13 inches high, 7 inches wide, and 6-1/2 inches deep.
The 2526BMWG set is not supplied fully assembled; each of the following parts must be
ordered separately:
l 526A Housing
l 2526BMG Telephone Set Base (equipped with handset and cord)
l 253C Aluminum Faceplate
l D180352 Mechanical Door Lock (optional)
l D180849 Weathertight connecting arrangement for single-line service
l D180850 Weathertight connecting arrangement for two-line service
l D180805 Switch and arm bracket without weathertight arrangement.
Figure 4-5.2526BMWG Voice Terminal
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							HARDWARE DESCRIPTION
7101A Voice Terminal (MD) (PEC 3170-00M)
The Model 7101A single-line analog voice terminal (Figure 4-6) is about 2-3/4 inches wide, 3-
1/2 inches high, and 8-1/2 inches deep. The set comes equipped with the following:
l Handset
l Touch-Tone Dial
l Message Indicator
l Tone Ringer with Volume Control
l Two Fixed Feature Buttons
—
Recall -Used to place a call on hold and to obtain recall dial tone for
Conference, Transfer, and other features accessible by feature access code.
—
Disconnect - Used to disconnect one call and immediately obtain dial tone for
another call.
Adjuncts: None
Figure 4-6.7101A Voice Terminal
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