Paradyne Comsphere 3511, User Manual

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COMSPHERE 3500 Series Data Service Units
3-8 July 1999 3510-A2-GN32-70
Digital Test (Point-to-Point)
Digital Test is a data disruptive test used to determine
if both DSUs and the DDS (Digital Data Service) network
between the DSUs are functioning properly (Figure 3-4).
Point-to-Point Digital Test Overview
After the remote DSU is put in Digital Loopback, this
test uses a test pattern generator that is built into the local
DSU. The generator sends a test message over the
network to a remote DSU where it is looped back
(Figure 3-4). The local DSU passes the received test
message to the comparator. The comparator checks the
message for errors. Isolated errors cause sporadic flashes
of the local DSU front panel FAIL indicator. Steady errors
cause the FAIL indicator to flash continuously.
The DTE cable for each DSU is not required to be
connected to do this test. However, to do this test, each
DSU must be powered on, connected to the network, and
the network line must be functional. The remote DSU
must be configured to allow remote Digital Loopback
testing (S1-6 open), or the test will fail.
Press the Remote Loopback (RL) and test pattern (TP)
test switches to start test at the local DSU. The test does
not require an attendant at the remote DSU location.
When the test is completed, press the RL and TP test
switches to return the DSU to normal.
Figure 3-4. Digital Test (Point-to-Point) Diagram