Verilink PRISM 3002 (34-00277) Product Manual - Manual (Page 33)

Maintenance Screen 4-11
The type of T1 loop is chosen by toggling the spacebar and is executed by pressing
Enter.
NET PLB (Payload Loopback)
The received network signal is looped back toward the network with signal
regeneration and framing and CRC regeneration. During the NET PLB, all 1s are
transmitted to the DTE. The NET PLB may be activated by receiving out-of-band
loop code on the network receive signal or by selection in the user interface
maintenance screen.
FAR PLB
A NET PLB can be activated on the remote end unit through this selection.
NET LLB (Line Loopback)
The received network signal is looped back toward the network with signal
regeneration only (framing and CRC intact). During the NET LLB, data from the
DTE is looped back to the DTE. The NET LLB may be activated by receiving
in-band or out-of-band loop code on the network receive signal, by the front panel
loop switch, or by selection in the interface maintenance screen.
Network Interface
To Network
From Network
RJ48C
Framer/Deframer multiplexer Receivers/Drivers
Receivers/Drivers
BERT Generator /
Detector
DTE (EIA-530 or V.35)
(100' max.)
Framer /Deframer
From
NET
To
NET
5
4
2
1 To
Ports
From
Ports
Normal Operation
Network Interface Framer /Deframer multiplexer Receivers /Drivers
NET
PLB
BERT Generator/
Detector
All ones
to DTE
EIA-530 or V.35
(100' max.)
From
NET
To
NET
To Network
From Network
RJ48C
5
4
2
1
To
Ports
From
Ports
Receivers /Drivers Framer /Deframer
Network PLB