2.
FDL
,
T1E1P
, and
T1E1L
commands require that
FRAMING = ESF
at both ends. In
addition, to receive or transmit
T1E1P
and
T1E1L
,
T1.403
must be set to
ON.
3.
Loopbacks established via FDL codes have priority over locally-established
loopbacks (except LS DTE loopbacks, which prevent Access-T from receiving the
network signal). In-band codes have priority over loopbacks established via FDL
codes.
4.
The RS449 interface includes a pin which allows the DTE to initiate a CS DTE
loopback at Access-T. A CS DTE loopback enabled by an external DTE will
always remove an active CS Line loopback and insert the CS DTE loopback.
Activating Loopbacks
To establish a loopback from a terminal, perform the following steps:
1.
Select
TEST
from the Main Menu Line.
2.
Select the appropriate loopback group:
PORT LOOP
or
LINE LOOP
.
•
If you select
PORT LOOP
, go to step 3.
•
If you select
LINE LOOP
, go to step 6.
3.
Select the appropriate port number (
PORT #).
4.
Select the port loopback option:
•
CSLOOP
brings up the following loopback options:
CSLINE
or
CSDTE
. Go to step 5.
•
REMOTE-UP
places the far-end Access-T into a CS Line loop-
back through a V.54 command. Go to step 9.
•
REMOTE-DOWN
removes CS DTE or CS Line loopback in pro-
gress at the far-end Access-T. Go to step 9.
5.
Select the desired channel-side loopback option:
•
CSLINE
loops received line-side data toward the far end.
•
CSDTE
loops received DTE-side data toward the DTE.
Go to step 9.
ACST-0351-005
Chapter 7
June 1996
Alarms, Reports, and Tests
7-29