H3C Technologies H3C MSR 50 - Manual (Page 231)

4-36
Figure 4-42 Extending an E1 75-ohm unbalanced coaxial cable
Router
Network
devices
such as DDN
DB-15
Coaxial connector
BNC BNC
75-ohm non-balanced coaxial cable
75-ohm E1 trunk cable
Router
Network
devices
such as DDN
DB-15
Coaxial connector
BNC BNC
75-ohm non-balanced coaxial cable
75-ohm E1 trunk cable
z
If the to-be-connected network device has a 120-ohm port, you need a 75-ohm-to-120-ohm
adapter or a 120-ohm cable instead.
When using a 120-ohm balanced twisted-pair cable, do the following:
z
If no cable extension is needed, connect the RJ-45 connector of the cable to the RJ-45 port on the
device.
z
If cable extension is needed, connect the RJ-45 connector of the cable to a network interface
connector, and the other end of the network interface connector to the device by using a 120-ohm
E1 trunk cable.
Figure 4-43 Extending an E1 120-ohm balanced twisted-pair cable
Router
Network
devices such
as DDN
DB-15
Network interface connector
RJ-45 RJ-45
120-ohm balanced twisted pair 120-ohm E1 trunk cable
Router
Network
devices such
as DDN
DB-15
Network interface connector
RJ-45 RJ-45
120-ohm balanced twisted pair 120-ohm E1 trunk cable
Step4 Power on the router, and check the behavior of the LINK LED on the module: OFF means fault occurs
on the line and the signal is not synchronized. Check the line status.
Connecting the interface cable of the FIC-4E1/FIC-4E1-F
Step1 Select the 4E1/E1 cable appropriate to the type of the port on the to-be-connected device, and
correctly set the DIP switch.
z
If the impedance of the to-be-connected port is 75-ohm, select E1 75-ohm unbalanced coaxial and
75-ohm 4E1 adapter cables, and set all the BITs of the DIP switch to the ON position (that is, the
port impedance is 75-ohm).
z
If the impedance of the to-be-connected port is 120-ohm, select E1 120-ohm balanced twisted-pair
and 120-ohm 4E1 adapter cables, and set all the BITs of the DIP switch to the OFF position (that is,
the port impedance is 120-ohm).
Step2 Insert the DB-25 connector of the 4E1 adapter cable into the to-be-connected port on the
FIC-4E1/FIC-4E1-F and tighten the thumbscrews.
Step3 Identify the sequence number of the DB-15 connector at the other end of the cable, and connect the
connector to an E1 cable.