3Com 3C13701 Module Manual page 90

3Com Router 5000 and Router 6000 v2.41
Module Guide
Caution:
Read the mark identifying a port before you connect a cable to it, making sure it is the
correct port. Wrong connection tends to damage interface modules and even the
Router;
Some protection measures are taken for Router 2 and 4-Port CE1/PRI MIM and
modules. Still, you are recommended to install a special lightning arrester at the
input end of the cable leading to the outdoors in order to protect the line against
lightning strikes more efficiently.
I. Connecting interface cable of 1E1/2E1 and modules
Step 1: Check the type of cable, and set the DIP switches module correctly;
Step 2: Plug the DB-15 connector of the cable into the port on the module;
Step 3: Connect the other end of the cable to the network device;
1) When using 75-ohm unbalanced coaxial cable,
Connect its BNC connector to the device to be connected directly, if cable
extension is not needed;
Connect its BNC connector to a coaxial connector and the other end of the
coaxial connector to the device to be connected through a 75-ohm trunk cable, if
cable extension is needed;
Caution:
Connect the local Tx wire in the cable to the remote Rx wire and the local Rx wire to the remote Tx wire.
Router
75-ohm non-balanced coaxial cable
Figure 3-45 Extending an 75-ohm unbalanced coaxial cable
DB-15
BNC
Coaxial connector
3-39
Multifunctional Interface Modules (Router 5000)
Network
BNC
devices
such as DDN
75-ohm E1 trunk cable
Chapter 3