31
3. Locate the lower of the two toggle switches on the front panel of the
Model 1080ARC and move it to the right. This will activate the V.52
BER test mode and inject a “511” test pattern into the local loop. If
any errors are present in the loop, the red “Error” LED will blink spo-
radically.
4. If the BER test indicates no errors are present, move the V.52 tog-
gle switch to the left, thus activating the “511/E” test with periodic
errors. If the test is working properly, the red “Error” LED will blink
regularly. A successful “511/E” test will confirm that the loop is in
place, and that the Model 1080ARC’s built-in “511” generator and
detector are working properly.
5. If the BER test indicates that errors are present, check to see that
the RS-232 cable connecting the DTE to the Model 1080ARC is
wired straight through, and is plugged in properly. Also, ensure that
the Model 1080ARC is configured properly. Then re-check your
DTE equipment. If you still have errors, call
Technical Support
at
(301) 975-1007
.
Remote Digital Loopback (RDL)
The Remote Digital Loopback (RDL) test checks the performance of both
the local and remote Model 1080ARCs, and the communication link
between them. Any characters sent to the remote 1080ARC in this test
mode will be returned back to the originating device. For example, char-
acters typed on the keyboard of the local terminal will appear on the local
terminal screen after having been passed to the remote Model 1080ARC
and looped back. To perform an RDL test, follow these steps:
1. Activate RDL. This may be done in two ways: First, by moving the
upper front panel toggle switch LEFT to “Remote”. Second, by rais-
ing pin 21 on the RS-232 interface.
2. Verify that the DTE equipment on the local end is operating properly
and can be used for a test.
3. Locate the lower of the two toggle switches on the front panel of the
1080ARC and move it to the right. This will activate the V.52 BER
test mode and inject a “511” test pattern into the remote loop. If any
errors are present in the loop, the red “Error” LED will blink sporadi-
cally.
