Remote Digital Loopback (RDL)
The Remote Digital Loopback (RDL) test checks the performance of both the local and remote Model 1082s, and the communication link between them. Any characters sent to the remote Model 1082 in this test mode will be returned back to the originating device (see Figure 14, below). For example, characters typed on the keyboard of the local terminal will appear on the local terminal screen after having been passed to the remote Model 1082 and looped back.
Local 1082 | Remote 1082 |
RDL initiated
Figure 14. Remote Digital Loop
Do not send a 511 test pattern from the test equipment when you connect external test equipment to the 1082.
Important
To perform an RDL test, follow these steps:
1.Activate RDL. This may be done in three ways:
—Move the front panel toggle switch down to Remote.
—Raise the RDL signal on the interface (see Appendix C, “Model 1082C and 1082D Interface Pin Assignments” on page 28).
Note Remote loopback cannot be activated until approximately 45 seconds after the two modems have linked to each other.
2.Perform a V.52 BER test as described in “Using the V.52 (BER) test pattern generator” on page 24. If the BER test equipment indicates a fault, and the Local Line Loopback test was successful for both Model 1082s, you may have a problem with the twisted pair line between the modems.You should then check the twisted pair line for proper connections and continuity.
Note The Remote Digital Loopback (RDL) will not work for 144 kbps. You must first set the units to 128 kbps or slower to use the RDL.
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