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CSU/DSU MS DBU
Use the number keys to type the address of the remote DSU, then press Enter.
The test-pattern selections are displayed. After a test pattern is selected,
the system briefly displays “Please Wait.”
Test Results
If the test is successful, the status menu is displayed. If not, “Unable to Execute
Test” is displayed.
Interpreting Test Results
If the unit is functioning properly, the test error count should be 0.
12.5 DBU Connection
When the CSU/DSU MS DBU is equipped with a dial-backup option, the DBU
Connection option appears as one of the Test menu selections. This test allows
the dial backup network to be tested while data is transmitted on the main line.
When this option is selected, choose a stored number, enter a number to dial, or
redial the last dialed number. After establishing DBU connection, the CSU/DSU
MS DBU designated at the answer unit is placed into loopback and a test pattern is
transmitted from the originate unit to the answer unit. Receive data is checked for
errors and the results displayed on the front panel. While running this test, errors
may be injected by pressing 2 and cleared by pressing 1. During the DBU test, the
Test LED is On.
NOTE
When running at a subrate over a 56-kbps or 64-kbps loop (or a 64-kbps
loop with Scrambler activated), the DSU will not send data during a DBU
test.
The DBU Answer Test option must be enabled. Enabling the DBU
Answer test does not affect the unit during dial backup.
DDS
Switched
DTE
LOCAL
DSU/CSU
DBU
DTE
LOCAL
DSU/CSU
Answer
Orig
M
U
X
M
U
X
DBU