Local Loop
After the 511/511E pattern times out, the ER led
with 511/511E
will begin flashing. It will remain this way until
(continued)
the pattern generator switch is turned off. Note
that the data at the local DTE and the remote
DTE are not valid. Because the data is
unframed there is no way for the framer to send
this data out to the DTE. This is an important
distinction because other Patton units will send
out the 511 pattern.
When the unit is placed into a Mode 2 Local
Loop, the 511/511E pattern generator on the
local unit is unavailable for transmission. As can
be seen from Figure 11, the 511/511E pattern
generator has no data path connections avail-
able. The 511/511E pattern generator is still
available on the remote unit. For more informa-
tion on the proper operation of this pattern gen-
erator please refer to the "Remote Digital Loop
with 511/511E" section.
Figure 14.
Block Diagram Local Loop Mode 1 with 511/511E
Figure 15.
Block Diagram Local Loop Mode 2 with 511/511E
21
Remote Digital
The Remote Loop uses the EOC channel (an
Loop
out-of-band signaling channel) to establish the
remote link. Upon the RDL switch being thrown
or DTE initiation, a RDL_ON Request signal is
sent to the remote unit. The Remote unit then
responds with an RDL Acknowledge command
and the link is established. Data originates at
the local DTE and is looped at the Remote
PROCESSOR back to the Local DTE. Note that
the data is also passed through to the Remote
DTE and is not squelched. When a Remote unit
enters RDL, it changes its' Restart timeout to
one minute (the reason will be explain in the
RDL with 511/511E section). If the line is discon-
nected, the local unit will Restart (NS led activat-
ed) after 4 - 6 seconds, but the Remote unit will
wait for one minute before it Restarts. Note that
the transmit data at the Remote DTE is ignored.
When the switch is thrown or the DTE removes
the RDL request, the local unit will transmit an
RDL_OFF Request to the Remote unit. The
local unit will keep its' TM led active until this
request has been completely sent out. If the
switch is thrown again before the completion of
the termination phase the switch will be ignored
until it is placed back into the normal position.
Figure 16.
Block Diagram Remote Loop
22
Pattern
Gen/Det
Loop
Contr
ol
Loop
Contro
l
Pattern
Gen/Det
Processor
Processor
Framer
Framer
Line
Pattern
Gen/Det
Loop
Contr
ol
Loop
Contro
l
Pattern
Gen/Det
Processor
Processor
Framer
Framer
Line
Pattern
Gen/Det
Loop
Contr
ol
Loop
Contro
l
Pattern
Gen/Det
Processor
Processor
Framer
Framer
Line
