Dbu Connection; Figure 4-19. Dbu Connection Test - ADTRAN DSU III TDM Manual

Chapter 4. Testing and Troubleshooting

DBU CONNECTION

When the DSU III TDM is equipped with a dial backup option, the DBU C
option appears as one of the T
NECTION
the dial backup network to be tested while data is passing on the DDS.
When this option is selected, choose a stored number or enter a number to dial.
After establishing DBU connection, the DSU III TDM designated as 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 dis-
played on the front panel.
While running this test, errors may be injected by pressing
pressing .
1
During the DBU test, the LEDs scan back and forth and the Test LED is on.
The DBU A
A
DTE
Tx Tx
Rx Rx
DTE
Tx Tx
Rx Rx
DTE
Tx Tx
Rx Rx
DTE
Tx Tx
Rx Rx
4-24
NSWER
test does not affect the unit during dial backup.
NSWER
LOCAL TDM
Tx Tx
Rx Rx
Tx
Rx
Tx
Rx
Tx
Tx
DBU
Rx
Rx
Tx
Rx
Answer
DSU III TDM User Manual
menu selections. This test allows
EST
test option must be enabled. Enabling DBU
DDS
Switched

Figure 4-19. DBU Connection Test

and cleared by
2
REMOTE TDM
x T
Tx
Rx x R
Tx
Rx
Tx
Test
Rx
Pattern
Generator
Tx
Tx
DBU
Rx
Rx
Test
Pattern
Tx
Detector
Rx
Originate
61200063L1-20
-
ON
DTE
x Tx T
Rx x R
DTE
x Tx T
Rx x R
DTE
Tx x T
x Rx R
DTE
Tx x T
Rx x R