Huawei Quidway AR 28 Series Installation Manual page 63

Quidway AR 28 Series Routers Installation Manual
Caution:
Check the interface mark before connection to avoid cable mis-insertion and router
damage.
When the E1 interface cable is routed outdoors, you need use the special lightning
protection unit at the input end to prevent possible damage.
Step 1: Check the E1 cable type and choose correct impedance value of the E1
interface through the inverter switch.
Step 2: Insert the DB-15 connector into the E1 interface of the router.
Step 3: Connect the other end to the right network devices.
For 75-ohm unbalanced coaxial cable
Connect the cable in this way:
If you choose only a single BNC connector, just connect the BNC connector to the peer
device.
If you choose two BNC connectors (for extending E1 interface cables), connect the
BNC connector of the 75-ohm unbalanced coaxial cable to a coaxial connector
assembly, which is connected to a 75-ohm E1 trunk cable. The 75-ohm E1 trunk cable
is then connected to the peer device.
Caution:
Connect the Tx end of the E1 interface cable to the Rx end of the peer unit, and Rx end
of the E1 interface cable to the Tx end of the peer unit.
75Ω unbalanced
Figure 4-28 Extending two E1 75-ohm unbalanced coaxial cables
If the peer device provides the 120-ohm interface, you need to use 75 −120-ohm
converter or 120-ohm cable.
DB-15
BNC connector
Coax connector
coax cable
assembly
Huawei Technologies Proprietary
Chapter 4 Installation of the Router
BNC
connector
75Ω E1
trunk cable
4-23
DDN