Loop (V.54 & Telco) Diagnostics; Operating Local Loopback (Ll) - Patton electronics 2701/I User Manual

6.3 LOOP (V.54 & TELCO) DIAGNOSTICS
The Model 2701/I offers three V.54 loop diagnostics. Use these diagnos-
tics to test the NTU and any communication links. These tests can be
activated via the front panel switches.

Operating Local Loopback (LL)

The Local Loopback (LL) test checks the operation of the local Model
2701/I, and is performed separately on each unit.
Figure 13. Local Loopback for a Network Termination Application
To perform a LL test, follow these steps:
1. Activate LL. This may be done by selecting local loop on the front
panel switch.
2. .Perform a V.52 BER (bit error rate) test as described on page 25. If
the BER test equipment indicates no faults, but the data terminal
indicates a fault, follow the manufacturer's checkout procedures for
the data terminal. Also, check the interface cable between the ter-
minal and the Model 2701/I.
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