3-8
PA-MC-T3-EC Port Adapter Installation and Configuration
OL-10589-02
Chapter 3 Removing and Installing Port Adapters
Cables and Connectors
Cables and Connectors
The interface connectors on the PA-MC-T3-EC are coaxial BNC types, with one connector for transmit
(TX) and one for receive (RX). The BNC connectors are transformer-coupled to the PA-MC-T3-EC line
interface unit (LIU), which is the analog physical interface on the PA-MC-T3-EC.
The pinout and signal descriptions for the BNC connectors on the PA-MC-T3-EC are as follows:
•
Transmit (TX)—Transmitted signals appear on the center contact, and the outer shield is grounded
for the 75-ohm 734A coaxial cable you attach to the TX BNC connector.
•
Receive (RX)—Received signals appear on the center contact, and the outer shield is grounded for
the 75-ohm 734A coaxial cable you attach to the RX BNC connector.
Caution
To prevent problems when long cable lengths are required, you
must
ensure that your 75-ohm coaxial
cables meet or exceed 734A specifications. See
“T3 Specifications” section on page 1-3
for supported
cable lengths.
Figure 3-5
shows the typical 75-ohm 734A coaxial cable pair recommended for use with the
PA-MC-T3-EC. Use one 75-ohm coaxial cable for each PA-MC-T3-EC connection: RX and TX.
Note
Cisco Systems does not supply cables with the PA-MC-T3-EC. You must supply your own cables.
Figure 3-5
75-Ohm 734A Coaxial Cable Pair
Connecting the Cables
This section describes the procedure for attaching 75-ohm 734A coaxial cables between the
PA-MC-T3-EC port adapter and your external DS3 equipment. To continue your PA-MC-T3-EC port
adapter installation, you must install the port adapter cables. The instructions that follow apply to all
supported platforms.
Connect the 75-ohm coaxial cables to the PA-MC-T3-EC as follows:
Step 1
Attach the 75-ohm coaxial cables directly to the BNC ports on the PA-MC-T3-EC. Attach one end of a
cable to the port labeled TX and one end of a second cable to the port labeled RX. (See
Figure 3-6 on
page 3-9
.)
1
TX
4
To DS3 equipment
2
RX
5
TX (out)
3
To PA-MC-T3-EC
6
RX (in)
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4
1
6
5
2