Loops and Patterns
The following section describes the Remote Loopback/BER test
modes.
Remote Digital
When Remote Loop/511 or Remote Loop/511/E
is enabled via the front panel switch, the
Remote unit’s Restart Timer is set to one
minute. This is because when the 511/511E
generator is initiated on the local unit, the
Remote framer begins seeing unframed pack-
ets. The Remote unit can not distinguish the
511/511E pattern from the line being disconnect-
ed, so the Restart Timer has been lengthened to
allow the pattern generator to function. Once the
511/511E test is started, the Local unit changes
its' Restart Timer to one minute. The pattern
originates within the Processor and is sent to
the Remote unit. It is then looped back to the
Local unit where it is evaluated for errors. After
45 seconds, the Pattern Generator will timeout
and stops sending the pattern. The ER led will
begin blinking until the user turns off the
511/511E switch.
Using the V.52 (BER) Test Pattern Generator
To use the V.52 BER tests in conjunction with the Remote Digital
Loopback tests, follow these instructions:
1.
Locate the Remote Loop/511 & Remote Loop/511E toggle
switch on the front panel of the unit and move it DOWN.
This activates the Remote Loop with V.52 BER and transmits
a “511” test pattern into the loop. If any errors are present,
the local unit’s red “ER” LED will blink sporadically.
2.
If the above test indicates no errors are present, move the
19
Compact mDSL Modem
20
Compact mDSL Modem
test switch V.52 toggle switch UP, activating the “511/E”
test with intentional errors present. If the test is working prop
erly, the local unit’s red “ER” LED will blink. A successful
“511/E” test will confirm that the link is in place, and that the
Compact mDSL Modem’s built-in “511” generator and detec
tor are working properly.
Pattern
Gen/Det
Loop
Contr
ol
Loop
Contro
l
Pattern
Gen/Det
Processor
Processor
Framer
Framer
Line
