Paradyne 317x E1 manual Starting a DTE Loopback, Starting a Repeater Loopback

Maintenance

Starting a DTE Loopback

The DTE Loopback command (DLB) loops the received signal on the DTE Drop/Insert port back to the DTE without change.

A DTE loopback can be activated and deactivated based on the state of an external contact on the DTE Drop/Insert port. If this option is enabled with the DTE Interface configuration option Extrn DLB, closing the contact activates a DLB. The DLB remains active until the contact is opened. Refer to the DTE Drop/Insert Interface section in Appendix D, Pin Assignments, for more information.

To perform a DTE loopback,

1.Press F2 to select Test from the top-level menu screen.

2.From the Test screen, press F2 to select Lpbk.

Test:
Rlpbk	Lpbk	Ptrns
F1	F2	F3

3.From the Loopback screen, press once to display the DLB selection on the screen.

Loopback:

Abort LLB PLB

F1 F2 F3

4. Press F3 to select DLB.

Loopback:

LLB PLB DLB

F1 F2 F3

Test Started appears on Line 2. If a DTE loopback is already in progress, the Already Active message appears. If an invalid combination of loopbacks is in progress, the error message Invld Test Combo appears (see Table 4-8 for valid loopback test combinations).

Starting a Repeater Loopback

The Repeater Loopback command (RLB) loops the signal being sent to the network back to the DTE Drop/Insert and data ports. The signal is looped back as close to the network interface as possible (after it has passed through the framing circuitry of the E1 DSU/CSU). Therefore, framing CRCs and BPVs are corrected.

To perform a Repeater loopback,

1.Press F2 to select Test from the top-level menu screen.

2.From the Test screen, press F2 to select Lpbk.

Test:

Rlpbk Lpbk Ptrns

F1 F2 F3

3170-A2-GB20-20 December 1996 4-17