3Com 3C13755-US - Router 5642 Installation Manual page 42

40 C 3: I
HAPTER NTRODUCING
Cables
R 5000 F MIM
OUTER AMILY S
Table 35 lists the selections that the 2-port E1/CE1/PRI MIM DIP switches enable
and how to configure them:
Table 35 Selection and Configuration of the 2-Port E1/CE1/PRI MIM DIP Switches
DIP
1BIT
2BIT
3BIT
4BIT
5BIT
6BIT
7BIT
8BIT
Only trained staff should change the position of a DIP switch. Change BIT1-8 to on
when connecting a 75-ohm cable. Change BIT1-8 to off when connecting a
120-ohm cable.
The 2-port E1/CE1/PRI MIM interface cable is a G.703-compliant (or E1) cable. You
must order the cable you need from 3Com when you order the interface card. To
prevent damage to your router and to avoid voiding your warranty, use only the
appropriate cable offered by 3Com.
There are two types of cables that can be used with this MIM: a 75-ohm
unbalanced coaxial cable, and a 120-ohm balanced twisted pair cable.
Configuration of
Selection 75-ohm impedance
75-ohm/120ohm On
On
On
On
On
RxRing grounding Off: RxRing is
mode grounded via
capacitance
On: RxRing is
grounded directly
RxShield grounding -
mode
SxShield grounding -
mode
Configuration of
120-ohm impedance
Off
Off
Off
Off
Off
-
On: RxShield is
grounded
Off: RxShield is not
grounded
Off: RxShield is
grounded via
capacitance
On: RxShield is
grounded directly.