Instruction manual

HARDWARE DESCRIPTION
Connectivity
System 25 requires 4-pair building wiring that conforms to AT&T Premises Distribution
System (PDS) specifications.
Various cords, cables, adapters, and connecting blocks are
used to facilitate the connection of equipment and associated cable and wire.
Major points of connectivity include the following:
● The system cross-connect field located on a wall adjacent to the system cabinets.
The field provides mounting space for the Trunk Access Equipment (TAE), Station
Interconnect Panels (SIPs), and Emergency Transfer Units (ETUs).
Refer to Section 5,
“Environmental Requirements” for a typical System 25 layout
including cross-connect field and associated equipment layout.
● 25-pair connectors located on the rear of each system cabinet.
● Modular jacks located at each work station provide modular connections for
terminals and associated adjuncts and auxiliary equipment. These jacks are
connected by building wiring to the SIP. Several wiring options are described below
Wiring Options: There are three basic PECs under which building (station) wiring is ordered:
● PEC 2781-004 covers wiring done on an hourly rate.
● PEC 2782-004 covers flat rate wiring.
● PEC 2783-004 covers firm price quote
Consult the 2780 section of the Sales Manual for restrictions and requirements before
ordering.
Trunk Access Equipment (TAE)
The TAE (Figure 4-24) provides for the connection of communications facilities such as Tie,
OPS, Ground Start, Loop Start, and DID trunks to the trunk ports of the system. Up to three
trunk CPs (except Tie Trunk CPs) can be connected to a 3-way splitter cable (PEC 2720-06X)
that concentrates the CP interfaces into one 25-pair cable. Up to two Tie Trunk CPs can be
connected to a 2-way splitter cable (PEC 2720-05X) that concentrates the CP interfaces into
one 25-pair cable. Each splitter cable connects to an interface block at the TAE.
Cables are either cut down or plugged into the TAE blocks. The other end of the cables plug
into the telephone company provided network interfaces (RJ21X or RJ2GX). Trunks and tie
lines are cut down by the telephone company at the network interface.
700A or 157B Blocks are usually used for the TAE connections (furnished by the installer).
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