32
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 remote BER test indicates that errors are present, and the
local analog loopback/BER tests showed that both Model
1080ARCs were functioning properly, this suggests a problem with
the twisted pair communication line connecting the two modems. A
common problem is improper crossing of the pairs. Also, verify that
the modular connections are pinned properly, and the twisted pair
line has continuity. If you still have errors, call
Technical Support
at
(301) 975-1007
.
Using The V.52 BER Test Independently
The Model 1080ARC's V.52 BER test can be used independent of the
V.54 loopback tests. This requires two operators: one to initiate and
monitor the test at both the local and the remote Model 1080ARC. To
use the V.52 BER test by itself, both operators should simultaneously fol-
low these steps:
1. 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 transmit a “511” test pattern to the other unit. If
any errors are present, the receiving modem’s red “Error” LED will
blink sporadically.
Note
For this independent test to function, the “511” switch on both
Model 1080ARCs must be turned on.
2. If the test indicates no errors are present, move the V.52 toggle
switch to the left, thus activating the “511/E” test with periodic errors
present. If the test is working properly, the receiving modem’s red
“Error” LED will blink regularly. A successful “511/E” test will confirm
that the link is in place, and that the Model 1080ARC’s built-in “511”
generator and detector are working properly.