26
2-WIRE SHORT-RANGE DSL LINE DRIVER (MDSL)
receiving unframed packets and assume that the line has gone down. During
test modes, the pattern generator is forced to time out before it can cause the
DSL link to go down.
• Loop Control: This part of the processor is used to control Remote Loopback
test mode. In a remote loop, the 511/511/E data is looped back to the line
and to the remote unit over the DSL span.
6.3.2 R
ESTART
P
ROCEDURE AND
T
IMEOUTS
The restart procedure is in place to allow the Line Drivers to re-establish a
connection after the framer begins seeing unframed packets. Table 6-3 shows the
amount of time the framer must see consecutive unframed packets before the Line
Driver will restart and try to establish a new line connection. The reason that there
are different restart times will become apparent after reading the rest of the
document. The 511/511E timeout shown refers to the amount of time the
511/511E pattern will be valid. At the end of this time the pattern will
automatically turn itself off and the normal data path will be re-established. The
ER LED will flash, indicating to the user that the test has timed out. The ER LED
will stop flashing once the 511/511E switch is placed into the normal position.
Table 6-3. Test mode timing.
Item
Elapsed Time (seconds)
Startup
50
Data Mode
4
511/511E Generator Enabled
60 (The generator will stop after
45 seconds.)
Remote End of an RDL
60
511/511E Timeout
45 (The pattern generator will
automatically turn off after 45 seconds.
The ER LED will flash until you turn off
the 511/511E switch.)
