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Tests
Channel Tests
076R155-000
SpectraComm 553 Fractional T1 DSU
4-13
Issue 7
Installation and Operation Manual
Channel Tests
Channel Self Test (End-to-End)
Channel Self Test turns on the channel-level test pattern generator and checker in the DSU. The test
can be initiated from the terminal interface or by SNMP control. Use of this test requires co-
ordination with the remote site, either to establish a loopback or to activate a test pattern generator
and checker (using the same pattern) for an end-to-end test.
The illustration shows Channel Self Test in use as an End-to-End Test. When coordinating this test
with the remote site, make sure that the same test pattern is selected in both units.
Figure 4-15
Channel End-to-End Self Test
Channel RDL with Self Test
Channel Remote Digital Loop (RDL) with Self Test commands the DSU to transmit an in-band
PN127 code that puts the remote DSU in Digital Loopback. The local DSU then turns on its chan-
nel- level test pattern generator and checker, and transmits its test pattern to the remote DSU which
loops it back. The local DSU checks for errors in the test pattern it receives back. Evaluates local
and remote units, and the T1 line.
Remote Digital Loop with Self Test can be commanded by means of the terminal interface, by
SNMP control, or by front panel switches.
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.
SC 553 DSU
Remote DSU
TPG
TPC
Framer
TX
Driver
Analog
Receiver
Network
Analog
Receiver
TX
Driver
Framer
TPC
TPG
TPG = Test Pattern Generator
TPC = Test Pattern Checker
DTE
Inter-
face
DTE
Inter-
face