Patton electronic 2710 - Manual (Page 36)

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To perform an RDL test, follow these steps:
1. Activate RDL. This may be done in two ways:
— Enter Remote Loop from the System Diagnostics/Statistics
menu and toggle the <Spacebar> until “RL” appears next to the
Remote Loop option.
— Activate the “RL” signal on the DTE. If you are not sure which
lead is the “RL” signal, please refer to Appendix D.
2. Perform a bit error rate test (BERT) using the internal V.52 generator
(as described in Section 5.3), or using a separate BER Tester. If the
BER test indicates a fault, and the Local Line Loopback test was
successful for both NetLink™s, you may have a problem with the
twisted pair line connection.
Central OfÞce Loops
The NetLink-T1™ also responds to central ofÞce initiated loop com-
mands. When in D4 framing mode, the NetLink-T1™ will implement the
“loop up” command when it recognizes the pattern “10000” in the data
stream for a minimum of 5 seconds. The “loop down” command is imple-
mented by the pattern “100” in the data stream for a minimum of 5 sec-
onds.
When operating in ESF framing mode, loopback commands are issued
via the Facility Data Link (FDL). The line loop message will cause a loop
back before data enters the framer portion of the CSU. The payload loop
message will cause the NetLink-T1™ to loop data after the framer por-
tion of the CSU.
The NetLink-T1™ will respond to Universal Loopback De-activate to
clear all central ofÞce loops.