User guide

Diagnostics 5-13

DTE/NET Loopback

To start this test:

1. Press DTE/LPBK to start the DTE/NET loopback test.

2. Press DTE/LPBK again to end the test.

Loopup Remote and Loopdown Remote

To start this test:

1. To run the test, press REMOTE LPBK UP to loopup the remote

Solo E1 DSU.

2. To loopdown the remote Solo E1 DSU, press REMOTE LPBK

DOWN.

When a test is running, the PWR/TEST LED shows yellow.

The Pattern Tests

Thoroughly test a line between two Solo E1 DSUs or between the customer

premises and the service provider with a pattern test:

¥ Use a pattern test in conjunction with a loop test by placing one Solo E1

DSU in loopback mode toward the network while the other generates

and detects the test sample.

The Solo E1 DSU generating the pattern detects and counts errors in the

pattern received and displays the errors.

¥ Run a pattern test by conÞguring both Solo E1 DSUs to perform the

same pattern test at the same time.

Both Solo E1 DSUs report detected errors in their respective received

signals, and you can determine from which direction (and which Solo

E1 DSU) the errors are occurring.

The tests also look for bit errors in both circuit directions when the remote

unit is looped up. In this case, the Solo E1 CSU transmits the QRW to the

E1 network, the remote unit loops it back to the Solo E1 CSU which

monitors the signal for errors. You can also use the QRW code to isolate a

E1 network problem to a speciÞc transmission direction. In this case, both

E1 transmission directions are monitored when the local and the remote

units transmit QRW (the remote is not put into loopback).