Fractional T1 Tandem Channel Unit Product Manual

The ADTRAN FT1-TDM is a central office (CO) unit used to deploy Nx64

kbps tandeming between channel banks within a CO, where N is a selectable

number of channels ranging from 2 to 12. The FT1-TDM plugs directly into

a standard AT&T D4 (or equivalent) channel bank, or SLC-96 when running

SLC Mode 1 or 3 operation. The unit occupies a single slot. No installation

wiring is required. Signals are provided to and from the channel bank or RT,

while PCM signals are provided to the local CO loop.

One ten-position switch pack is used to configure the mode of operation

for the unit. Configuration is performed by manually selecting each option

switch.

Bandwidth is set by the FT1-TDM in contiguous or alternating time slots.

The front panel of the FT1-TDM contains DS0 splitting Bantam jacks.

The metallic splitting jacks provide an intrusive, signal-interrupting access

to the first DS0 channel. The Bantam jacks allow connection of a Tele-Path

Industries 108/109 RT II (or equivalent) test set through one DS0 channel

at 64 kbps for functions such as sending and receiving bit error rate signals,

and latching loopback sequences.

There are two loopbacks available to the FT1-TDM. NEAR loopback loops

the received T1 signal back to the T1 transmitter at the DSX-1 interface.

FAR loopback loops the received PCM data back to the PCM backplane.

NEAR loopback is a digital loopback toward the DSX-1 interface. This loop-

back is initiated by the DS0 latching loopback command or by the front

panel NEAR DIP switch. FAR is a digital loopback toward the PCM interface.

This loopback is initiated by the DS0 latching loopback command or by the

front panel FAR DIP switch. When the FT1 circuit is looped, all DS0s in use

will be looped back toward the PCM backplane and an all 1s signal will be

sent to the DSX-1 interface.

If needed, bi-directional tandem latching loopbacks are available by

looping a remote FT1-TDM and sending the sequence from a local unit.

The latching loopback sequence can also be initiated through the front

panel Bantam jacks.

PRODUCT FEATURES

■ Intra-office tandeming between

D4 channel banks

■ 12 DS0 capability

■ Multiple loopbacks and

diagnostics

■ Compatible with standard

AT&T D4

FT1-TDM

FRACTIONAL T1 TANDEM CHANNEL UNIT

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FT1-TDM F R A C T I O N A L T 1 TA N D E M C H A N N E L U N I T P R O D U C T F E AT U R E S ■ Intra-office tandeming between D4 channel banks ■ 12 DS0 capability ■ Multiple loopbacks and diagnostics ■ Compatible with standard AT&T D4 The ADTRAN FT1-TDM is a central office (CO) unit used to deploy Nx64 kbps tandeming between channel banks within a CO, where N is a selectable number of channels ranging from 2 to 12.
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