3com MSR 20 User Manual
46
C
HAPTER
2: S
MART
I
NTERFACE
C
ARDS
Figure 39 Default setting of DIP switches
Description of DIP switch settings is given in the following table:
c
CAUTION:
■
It is recommended to select the DIP switch in this way: when connecting
75-ohm cable, flip BIT1-8 to ON, and when connecting 120-ohm cable, flip
BIT1-8 to OFF.
75-ohm cable, flip BIT1-8 to ON, and when connecting 120-ohm cable, flip
BIT1-8 to OFF.
■
By default, all of the DIP switches are factory-configured to ON, that is, the
impedance of E1 interface is 75-ohm.
impedance of E1 interface is 75-ohm.
Interface LEDs
The following figure illustrates the SIC-1VE1 panel.
Table 21 Description of DIP switch settings of SIC-ERRI/SIC-1E1-F
DIP Description
Configuration of
75-ohm impedance
75-ohm impedance
Configuration of
120-ohm impedance
120-ohm impedance
1BIT 75-ohm/120-ohm
selection switch
ON OFF
2BIT
ON OFF
3BIT
ON OFF
4BIT
ON OFF
5BIT
ON OFF
6BIT RxRing
grounding
mode selection
switch
switch
OFF: RxRing is
grounded via
capacitance.
grounded via
capacitance.
ON: RxRing is
grounded directly.
grounded directly.
-
7BIT RxShield
grounding
mode selection
switch
switch
- ON:
RxShield
is
grounded.
OFF: RxShield is not
grounded.
grounded.
8BIT SxShield
grounding
mode selection
switch
switch
- OFF:
RxShield
is
grounded via
capacitance
capacitance
ON: RxShield is
grounded directly.
grounded directly.
on
1
2
3
4
5
6
7
8