Interface Card and Interface Module Manual
H3C MSR 20/30/50 Series Routers
Chapter 3 Multifunctional Interface Modules
3-25
DIP
Description
Configuration of
75-ohm
impedance
Configuration of
120-ohm
impedance
8BIT
SxShield
grounding mode
selection switch
—
OFF: RxShield is
grounded via
capacitance
ON: RxShield is
grounded directly.
Caution:
z
It is recommended to select the DIP switch of MIM-1E1/MIM-2E1/MIM-4E1 and
MIM-1E1-F/MIM-2E1-F/MIM-4E1-F modules in this way: when connecting 75-ohm
cable, flip BIT1-8 to ON, and when connecting 120-ohm cable, flip BIT1-8 to OFF.
Positions of DIP switches can only be changed by the trained personnel.
z
By default, all of the DIP switches of MIM-1E1/MIM-2E1/MIM-4E1 and
MIM-1E1-F/MIM-2E1-F/MIM-4E1-F modules are factory-configured to ON, that is,
the impedance of E1 interface is 75-ohm.
3.6.6 Connecting the Interface Cable
Caution:
z
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;
z
Some protection measures are taken for MIM-1E1/MIM-2E1/MIM-4E1 and
MIM-1E1-F/MIM-2E1-F/MIM-4E1-F 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 MIM-1E1/MIM-2E1 and
MIM-1E1-F/MIM-2E1-F/MIM-4E1-F modules
Step 1: Check the type of E1 cable, and set the DIP switches of MIM-1E1/MIM-2E1 or
MIM-1E1-F/MIM-2E1-F module correctly;
Step 2: Plug the DB-15 connector of the E1 cable into the E1/FE1 port on the module;