4-9
Cisco Network Modules Hardware Installation Guide
OL-2485-20
Chapter 4 Connecting Fast Ethernet-PRI Network Modules
1-Port Fast Ethernet and 1- or 2-Port Channelized E1/ISDN PRI Balanced or Unbalanced Network Modules
Configuring Unbalanced Mode
To configure the network module for unbalanced mode, follow these steps:
Step 1
Turn off electrical power to the router. However, to channel ESD voltages to ground, do not unplug the
power cable. Remove all network interface cables, including telephone cables, from the rear panel.
The following warning applies to routers that use a DC power supply:
Warning
Before performing any of the following procedures, ensure that power is removed from the DC
circuit. To ensure that all power is OFF, locate the circuit breaker on the panel board that services
the DC circuit, switch the circuit breaker to the OFF position, and tape the switch handle of the
circuit breaker in the OFF position.
Statement 7
Step 2
Loosen the module captive mounting screws, using a Phillips or flat-blade screwdriver.
Step 3
Hold the captive screws between two fingers, and pull the network module toward you until it slides free
of the chassis.
Step 4
Set the network module on an ESD-preventive mat.
Step 5
Using needlenose pliers, set jumpers J5 through J9 on the top terminal block to the 75-ohm position. Set
jumpers J4 through J8 on the bottom terminal block to the same 75-ohm position. (See
Figure 4-16
.)
Figure 4-16 Jumper Insertion
Figure 4-17
shows the top terminal block set to unbalanced (75-ohm) position.
24064
TE
RM
IN
A T
IO
N
J9
J8
J7
J6
J5
J4
CA
BL
E S
HIE
LD
12
0
75
TERMINA
TION
J9
J8
J7
J6
J5
J4
CABLE SHIELD
120
75
Top card
Place jumper
in this position
first
Place jumper
in this position
last
Bottom card