Huawei Quidway AR 28 Series Installation Manual page 62

Quidway AR 28 Series Routers Installation Manual
Figure 4-27 E1 120-ohm balanced twisted pair cable
Note:
You can also choose to attach both ends with RJ-45 connectors, for extending two
120-ohm balanced twisted pair cables.
In addition, you can order 75–120-ohm adapter if needed.
For the pinouts of E1 interface cable, see Low-End and Mid-Range Series Routers
Cable Manual.
Note:
E1 interface cable, coaxial connector, network interface connector and 75–120-ohm
adapter are optional, so you have to order them as needed when purchasing the AR
28-13.
3) Impedance inverter switch
Impedance inverter switch is also available, through which you can choose the
interface impedance value.
Turn on the switch to change the interface impedance to 75-ohm, and then you
need to connect the 75-ohm cable.
Turn on the switch to change the interface impedance to 120-ohm, and then you
need to connect the 120-ohm cable.
4) Connecting the E1 interface cable
Huawei Technologies Proprietary
4-22
Chapter 4 Installation of the Router