Reference Guide
IMACS System Release 5.1.9
7-15
WAN Card
WAN Card User Screens and Settings
Figure 7-10. DS0 Time Slot Loopback
LB ADDR
The Loopback Address setting, when used in conjunction with the Channel Loopback setting,
specifies which time slot will be looped back. Only one time slot may be looped back at a time
for each WAN T1/E1 link. The options for T1 lines are
1
to
24
. For E1 lines, the options are
1
to
31
.
LB GEN
The Loopback Generate setting generates out-of-band diagnostic codes that are sent to the
remote equipment. These codes are ANSI T1.403 compatible with T1 networks, and allow
you to command a latching loopback at remote DS1 equipment. The options are
off
,
llb
(Line
Loopback),
plb
(Payload Loopback), and
nlb
(Network Loopback). The
plb
setting is a
loopback of the entire signal except the framing bits.
Selecting
off
generates a loopback deactivate command corresponding to the last activation
command generated. e.g. if you send a
plb
command and then send an
off
command, the
off
command would be payload deactivate.
Note that the actual transmission of the command happens after you press ‘
s
’ for
Save
. If you
have already sent one of the loopback activation commands, it is recommend that you send an
off
command before sending another loopback activation command. e.g. this set of selections
plb, off, llb, off
transmits the following commands: payload activate, payload deactivate, line
activate, and line deactivate.
PCM Bus
Network
WAN Card
T1/E1
