PairGain PG-Flex, Manual

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Troubleshooting
102
PG-Flex Metallic Test Access
PG-Flex provides a break-out function and automatic line test support used to diagnose a faulty
subscriber connection. Manual subscriber line metallic access is activated and deactivated via the
Craft Port Interface. Test Desk support for 4TEL line testing is handled via recognition of control
voltages to the Channel Under Test. Automatic line testing is accomplished by supporting the Pair
Gain Test Controller (PGTC).
Manual Subscriber Line Metallic Access
Manual test activation is accomplished by selecting the line access function, then channel card and
channel number from the Metallic Access Menu. The manual line metallic access functions
available are: COT Bridging, COT Looking-In, COT Looking-Out, RT Bridging, RT Looking-In,
RT Looking-OUT, and Subscriber Bypass.
Manual subscriber line metallic access can aid in isolating single-channel failures in channel cards
from the central office—used prior to dispatching a service technician to the field. In particular,
COT and RT “looking-in” functions can be used to check for dial tone and ring signals at the central
office and subscriber drop terminations.
Test Desk Activation
Test desk activation is activated by receipt of +116VDC to the Tip lead of the Central Office
channel unit for the Channel Under Test. The POTS connection from the CO switch to the Channel
Under Test is dropped and the connection is routed to the Metallic Bypass line.
The routing is completed at the Remote Terminal end where the Metallic Bypass line is connected
to the subscriber POTS circuit. In effect, PG-Flex is removed from this particular subscriber
connection. The phone company personnel can then perform whatever testing is necessary to verify
the condition of the subscriber line.
Deactivation is accomplished upon detection of -116 Vdc to the Tip lead of the Metallic Bypass line
at the COT line unit. The subscriber connection is then restored to the PG-Flex system.
4TEL test activation is only accomplished with the FAU-728 Alarm Card.
Automatic Line Metallic Access
Automatic line metallic access is provided by the use of the FPI-729 PGTC Interface Unit. The
PGTC Interface card handles and provides the handshakes necessary to establish and maintain the
connections for the Pair Gain Test Controller to perform its stimulus and measurement testing of
the Channel Under Test.
COT and RT Bridging functions are not available for ISDN cards due to the low impedance
nature of the bridging relays. The low impedance connection would cause data drop-outs or
circuit disconnections to ISDN circuits.