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Tests
Channel Tests
076R155-000
SpectraComm 553 Fractional T1 DSU
4-15
Issue 7
Installation and Operation Manual
Channel Remote Digital Loop
Channel Remote Digital Loop commands the DSU to transmit an in-band PN127 code that puts the
remote DSU in Digital Loopback. The test provides a path through the DSU, the network, and the
remote DSU for an externally generated test signal, as shown in
. Evaluates local and
remote units, and the T1 line.
Either the DTE or a bit error rate tester (BERT) connected to the DTE interface can supply and
check a test signal. The device that supplies the test signal is responsible for error detection and
reporting.
Remote Digital Loop can be commanded by means of the terminal interface, by SNMP control, by
means of front panel switches, or by the RL lead (Pin 21) of the DTE interface.
Note
Tests cannot be performed by means of front panel switches when the front panel has been inhibited by
an SNMP controller or by the terminal interface. Front panel enabled is the default condition. The DTE
interface RL lead can only command Remote Test if Channel EIA Test Leads has been enabled by an
SNMP controller or by the terminal interface. The default condition is disabled.