Paradyne 316x manual Starting a Payload Loopback, Starting a DTE Loopback, DSU ESF Stat Test Cnfig

Maintenance

Starting a Payload Loopback

The Payload Loopback command (PLB) loops the received signal on the network interface back to the network. The signal is looped back as close to the DSX-1 Drop/Insert port (DTE) as possible (after it has passed through the framing circuitry of the DSU/CSU). Therefore, framing CRCs and BPVs are corrected. If bit stuffing is enabled, pulse density is enforced.

To perform a Payload loopback,

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

DSU ESF

Stat Test Cnfig

F1 F2 F3

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

Test:

Rlpbk Lpbk Ptrns

F1 F2 F3

3.From the Loopback screen, press F3 to select PLB.

Loopback:

Abort LLB PLB

F1 F2 F3

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

Starting a DTE Loopback

The DTE Loopback command (DLB) loops the

received signal on the DSX-1 Drop/Insert port (DTE) back to the DTE without change.

A DTE loopback can be activated and deactivated based on the state of an external contact on the DSX-1 Drop/Insert port (DTE). If this option is enabled with the DTE Interface configuration option Extrn DLB, closing the contact (relay contact sense and relay contact return) activates a DLB. The DLB remains active until the contact is opened. Refer to the DSX-1 Port DTE Interface section in Appendix D, Pin Assignments, for more information.

3160-A2-GB22-10 December 1996 4-7