ADTRAN DSU 56 user manual DTE with Test Pattern TP

Chapter 3. Test Modes

To initiate the DTE ONLY test, perform the following steps:

1.Press SELECT once to turn on the DTE test indicator.

2.Press TEST while the test indicator is on.

3.To terminate the test, press TEST.

Test data from the terminal or test equipment is routed through the DTE section of the DSU 56/64 and then to the output of the loop transmitter section where the signal is encoded for transmission. The output of the loop transmitter is coupled back to the loop receiver input. The received test signal is then decoded and returned to the terminal or test equipment where it is checked for any bit errors.

DTE WITH TEST PATTERN (TP)

The DTE WITH TP test is similar to the DTE ONLY TEST described in Figure 3-1 on page 3-2. It is initiated at the local DSU 56/64 and is used to independently test the operation of the DSU 56/64.

To initiate the DTE WITH TP test, perform the following steps:

1.Press SELECT twice to turn on both the DTE and PTRN test indicators.

2.Press TEST while these test indicators are on.

3.To terminate this test, press TEST.

Instead of using data from the terminal or test equipment, this test utilizes an internal test pattern generator and detector in the DSU 56/64. The loopback point and the data paths for this test are illustrated in Figure 3-2 on page 3-4.

61200062L1-1 DSU 56/64 User Manual 3-3