Filter
Top Products
25
Up mode. Note that once the 511/511E-pattern generator is
started the Restart timer is changed to one minute (only on the unit
which has the pattern enabled). If both units enable the 511/511E
pattern within 4 seconds of each other, both units will be transmit-
ting and receiving the 511/511E pattern. Both framers are now
receiving unframed data and will restart after one minute. The 511/
511E pattern generators will TimeOut after 45 seconds re-enabling
the normal data path. The ER led will begin flashing until the user
terminates the test.
Using the V.52 (BER) Test Pattern Generator
To use the V.52 BER tests in conjunction with the Remote Digital Loop-
back tests (or with Local Line Loopback tests), follow these instructions:
1. Locate the “511/511E” toggle switch on the front panel of the 1088
and move it DOWN. This activates the V.52 BER test mode and
transmits a “511” test pattern into the loop. If any errors are present,
the local modem’s red “ER” LED will blink sporadically.
2. If the above test indicates no errors are present, move the V.52 tog-
gle switch UP, activating the “511/E” test with errors present. If the
test is working properly, the local modem's red “ER” LED will blink.
A successful “511/E” test will confirm that the link is in place, and
that the Model 1088’s built-in “511” generator and detector are work-
ing properly.
Note The above V.52 BER tests can be used independently of the
Remote Digital Loopback tests. This requires two operators: (1)
to initiate and monitor the tests at the local Model 1088, and (2)
to do the same at the remote Model 1088. In this case, the test
pattern sent by each Model 1088 will not be looped back, but will
be transmitted down the line to the other Model 1088. While one
operator initiates test, the other monitors for errors.