3Com 3C63100-AC-C - PathBuilder S600 Bridge/router Reference Manual page 35

Figure 8 DS3 UNI Module Connection
DS3 Service
Once you have connected the module, verify the front-panel indicator sequence
illustrated in Figure 9. The DS3 UNI module features the following front panel
indicators in addition to the common system LEDs:
LOS (RED)—Powers up in the "off" state and illuminates when a LOS (Loss of
Signal) condition is detected on the incoming DS3. The LOS LED is off if a signal is
present. It reflects the LOS state of the DS3 in real time (no integration of the state
is needed).
A LOS condition sometimes occurs when the DS3 cell encapsulation (PLCP or
Clear) is set incorrectly. For details about setting DS3 cell encapsulation, see
"Configuring the DS3 UNI Module" in Chapter 5.
LOF (RED)—Powers up in the "off" state and illuminates when a LOF (Loss of
Frame) condition is detected on the incoming DS3. The LOF LED is off when the
signal is in frame. It reflects the LOF state of the DS3 in real time (no integration of
the state is needed).
LOCD (RED)—Powers up in the "off" state and illuminates when a LOCD (Loss of
Cell Delineation) condition is detected on the incoming DS3 under HEC (Header
Error Control) framing. The LOCD LED is off when delineations are obtained. It
reflects the LOCD state of the DS3 in real time (no integration of the state is
needed).
Step 4: Connect I/O Cabling and Wiring
RX
TX Out
In
75 ohm coax
0-225 ft or 225-450 ft
TX Out
TX In
DS3
CSU or CPE
35
Slot 6
Slot 5
Slot 4