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)
—...

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...

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...

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...

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...

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...

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...

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)
4-18 

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...

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.
—...