Operating Remote Digital Loopback RL | Patton electronic 2701/D

2.Verify that the data terminal equipment is operating properly and can be used for a test.

3.Perform a V.52 BER (bit error rate) test as described in section “Using the V.52 (BER) Test Pattern Generator” on page 20. If the BER test equipment indicates no faults, but the data terminal indi- cates a fault, follow the manufacturer’s checkout procedures for the data terminal. Also, check the interface cable between the terminal and the Model 2701.

Operating Remote Digital Loopback (RL)

The Remote Digital Loopback (RL) test checks the performance of both the local and remote NetLink-E1™, as well as the communication link between them. Any characters sent to the remote NetLink-E1™ in this test mode will be returned back to the originating device (i.e, characters typed on the keyboard of the local terminal will appear on the local termi- nal screen after having been passed to the remote NetLink-E1™ and looped back).

Figure 8. Remote Loop in a Network Extension Application

There are two Remote Loops that can be initiated from the NetLink-E1 unit: (1) V.54 Loop, and; (2) CSU Loop. The user can select the type of loop that can be initiated by Switch S2-4. When a loopback is initiated this is the type of loop that the unit uses to loop up the remote unit and which type of loop the unit will respond to.

To perform an RDL test, follow these steps:

1.Activate RDL. This may be done in two ways:

—Activate the “RL” signal on the DTE (2701/B and 2701/C only). If you are not sure which lead is the “RL” signal, please refer to Appendix B or C, depending on the version you are using.