Verilink FrameStart FSD (34-00291.F) Product Manual - Manual (Page 36)

30 D D S C S U / D S U a n d T 1 C S U / D S U a n d F r a m e S t a r t F S E
Enable LCL (DDS CSU/DSU only). As shown in Figure 4.9, the received
network signal is looped back toward the network. During the LCL loop, the
DTE is looped on itself.
Figure 4.9 Enable LCL
Enable PLB (T1 CSU/DSU and FrameStart FSE only). (Payload
Loopback) - As shown in Figure 4.9, the received network signal is looped
back toward the network with signal regeneration, framing and CRC
regeneration. During the NET PLB, the DTE is looped on itself. In T1 circuits
the NET PLB is activated by receiving out-of-band loop code on the network
receive signal (E1 has no remote PLB enable) or by selection in the user
interface maintenance screen.
Figure 4.10 Enable PLB
Enable V54. As shown in Figure 4.11, the network signal is looped back
toward the network after the rate adaptation FIFOs. In this mode, the DTE is
looped back on itself. This loop can be invoked from the unit or the remote-
end equipment.
Figure 4.11 Enable V54
Network Framer / Receivers/
BERT
DTE
From
NET
To
NET
To
Port
From
Port
(Winchester-type
Connector)
Drivers Deframer Interface
Generator/
Detector
To Network
RJ-48C
From Network
Network Framer / Receivers/
BERT
DTE
From
NET
To
NET
To
Port
From
Port
(Winchester-type
Connector)
Drivers Deframer Interface
Generator/
Detector
To Network
RJ-48C
From Network
Network Framer / Receivers/
BERT
DTE
From
NET
To
NET
To
Port
From
Port
(Winchester-type
Connector)
Drivers Deframer Interface
Generator/
Detector
To Network
RJ-48C
From Network