ADTRAN 1200270L1, Manual

Page: 91 / 132

Chapter 11. Testing and Troubleshooting
61200270L1-20 DSU III ARdc User Manual 11-13
Figure 11-8. Initiating a Loop Only Test
Interpreting Test Results
The L
OOP
O
NLY
test is used for the purpose of looping the DDS circuit back
to the telco. No test results are available from the local DSU III ARdc.
DTE Only
The DTE O
NLY
test provides a method for testing both the DTE interface
drivers and receivers of the local DSU III ARdc plus its loop transmitter
and receiver. For this test, the loop transmit data is connected to the loop
receive data at a point close to the physical network interface. This test can
be used to verify proper operation between the local DTE and the local
DSU III ARdc.
1=DTE & LOOP (LL)
2=LOOP ONLY (RT)
3=DTE ONLY
4=DTE WITH TP
1=LOCAL UNIT 5=TEST PATTERN
2=TEST 6=SELF TEST
2=REMOTE UNIT
When this test is implemented, the far unit receives an OOS/
OOF message from the network and enters an alarm state.