Operating Remote Digital Loopback RDL | Patton electronic 2073RC

Operating Remote Digital Loopback (RDL)

The Remote Digital Loopback (RDL) test checks the performance of both the local and remote 2073RC as well as a point-to-pointcommunication link between them. Any characters sent to the remote 2073RC 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 terminal screen after having been passed to the remote 2073RC and looped back).

Figure 13. Remote loopback

1.The Remote Loop (V.54) can be initiated from the 2073RC unit: either by activating the RDL signal on the DTE (if you are not sure which lead is the RDL signal, refer to Appendix B “Interface Pin Assignment” on page 25) or by toggling the top front panel switch towards the label “RDL”. The Yellow TM (Test mode) LED will turn on to indicate a successful RDL.

2.Perform a bit error rate test (BERT) using the internal V.52 generator (as described in section “Bit Error Rate (V.52) Diagnostics”, turn the Bit error rate (V.52) diagnostics on or using a separate BER Tester.If the BER test indicates a fault, and the Remote Line Loopback test was successful for both 2073RC you may have a problem with the twisted pair line connection.

Bit Error Rate (V.52) Diagnostics

The 2073RC offers V.52 Bit Error Rate (BER) test patterns that can be invoked along with the LLB and RDL tests to evaluate the unit(s) and the communication links. When a 511 test is invoked, the 2073RC generates a pseudo-random bit pattern of 511 bits, using a mathematical polyno- mial.The receiving 2073RC then decodes the received bits using the same polynomial.If the received bits match the agreed upon pseudo-ran- dom pattern, the 2073RC and the communications link are functioning properly. 511 or 511/E is initiated by setting the bottom front panel switch towards the label ‘511’ or 511E” respectively. The Yellow TM (Test mode) LED will turn on to indicate activation of the 511 or 511E test modes.