3Com Router Module Guide
Chapter 4
4-56
Figure 4-54
75-to-120-ohm adapter (with BNC connectors)
Note:
To extend E1 120-ohm balanced twisted-pair cables, use network connectors.
E1 120-ohm balanced twisted pair cables, network connectors, and 75-to-120-ohm
adapters are optional accessories; they are provided only when ordered.
4.16.5 Connecting the Interface Cable
Caution:
If outdoor cabling is involved, consider to install a special lightning arrester at the input
end of the interface cable for better lightning protection.
Before you connect a port, read its label carefully; a wrong connection can cause
damages to the interface card and even the device.
Step 1: Insert the DB-15 connector of the cable into the DB-15 port on the ROUTER
1-PORT E1 VOICE FIC and tighten the thumbscrews.
Step 2: Connect the RJ-45 connector at the other end of the cable as follows:
z
If the impedance of the to-be-connected port is 120-ohm, and if cable extension is
not required,
Directly plug the RJ-45 connector into the port.
z
If the impedance of the to-be-connected port is 120-ohm, and if cable extension is
required,
Extend the E1 120-ohm balanced twisted-pair cable with a network connector, as
shown in the following figure.
