Patton electronics 2701/B User Manual

Also see for NetLink 2701: Specification sheet

Patton electronics 2701/B User Manual Manual pdf 18 page image

18the identical pattern. When it receives the correct pattern, theLED will turn off. If error insertion is on, the LED will blink once asecond if everything is operating properly.TM(Active Yellow) Solid Yellow indicates an Active Test Mode. Theunit may be placed in test mode by the local user or by theremote user.5.3 LOOP (V.54 & TELCO) DIAGNOSTICSThe Model 2701 offers three V.54 loop diagnostics. Use these diagnos-tics to test the NTU and any communication links. These tests can beactivated via the front panel switches or via signals on the Model 2701/Band C serial port interface.Operating Local Loopback (LL)The Local Loopback (LL) test checks the operation of the local Model2701, and is performed separately on each unit. Any data sent to thelocal Model 2701 in this test mode will be echoed (returned) back to theuser device (i.e., characters typed on the keyboard of a terminal willappear on the terminal screen).Figure 7. Local Loopback for a Network Termination ApplicationTo perform a LL test, follow these steps:1. Activate LL. This may be done in one of two ways:— Place the switch on the front panel in the “Local” position.— Activate the “LL” signal on the DTE (2701/B and 2701/C only).If you are not sure which lead is the “LL” signal, please refer toAppendix D.