Setting The Fixed E1 Interface Impedance - H3C MSR 20-1X Installation Manual

Setting the Fixed E1 Interface Impedance

CAUTION:
Positions of DIP switches should be performed by H3C personnel or an Authorized H3C partner.
By default, the impedance of the fixed E1 interface on MSR 20- 1 2 is 75-ohm. Using the internal DIP
switches, users can change the interface impedance from 75-ohm to 120-ohm.
Figure 46 Default setting of DIP switches
1
2
3
4
5
6
7
8
Description of DIP switch settings is given in the following table:
Table 2 Description of DIP switch settings
DIP
1BIT
2BIT
3BIT
4BIT
5BIT
6BIT
7BIT
8BIT
on
Description
75-ohm/120-ohm
selection switch
RxRing grounding mode
selection switch
RxShield grounding
mode selection switch
SxShield grounding
mode selection switch
Configuration of
75-ohm impedance
ON
ON
ON
ON
ON
OFF: RxRing is grounded
via capacitance.
ON: RxRing is grounded
directly.
—
—
63
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.