PairGain PG-Flex, Manual

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Central Office Terminal Equipment
5
PGTC Interface Unit
The FPI-729 List 1 Pair Gain Test Controller (PGTC) Interface Unit provides a common interface
between the PGTC and the PG-Flex system under test. The FPI provides the translation facilities
necessary to satisfy the discrete line communications to and from the PGTC, and the serial message
protocol to and from the COT line unit in test.
The FPI-729 also provides Craft Port Multiplexer capabilities; a multiplexed test jack for subscriber
line access; and handles the CO supplied Composite Clock for digital service cards.
The PGTC Interface Card is used in situations where digital data service cards (ISDN, DDS) are
used in the shelf and the PGTC function is required. The FPI-729 is used to provide an 8 kHz sync
signal to all COT line units installed in the COT Shelf. The 8 kHz sync signal is derived from the
Central Office supplied Composite Clock. The Alarm Unit reports a loss of the Composite Clock
signal. The severity of the failure is user definable (Major, Minor, Disabled).
COT Line Unit
A PG-Flex system is comprised of one line unit and one or more channel units at both the CO and
remote terminals. The COT line unit takes the CO battery and converts it to the voltages necessary
to operate the COT line unit and channel units, as well as for powering the remote terminal. The
line unit also includes the high-bit digital-rate subscriber line (HDSL) transceivers and common
control.