Table C-1. AUI Cable Pin Chart (Continued)

12

DI-B

Receive -

 

 

 

13

VP

Power +

 

 

 

14

VS

Reserved

 

 

 

15

C0-B

Reserved

 

 

 

Shell

Protective ground

Shield terminated to

 

 

connector shell

 

 

 

Transceiver Cable Differences

Because AUI Transceiver cables may be built to any of three Ethernet standards (V1.0, V2.0, and IEEE 802.3), signal differences may occur between different types of transceiver cables. These three standards also affect the shielding and grounding of the cables and the size of the wires used in the cables.

Shielding and Grounding

The most significant difference among AUI cables occurs in the shielding and grounding of the individual signal and power pairs. IEEE 802.3 and Ethernet V2.0 specify a requirement for signal isolation due to AC-coupling of the AUI connection, whereas the V1.0 standard does not include this requirement.

The three standards specify different techniques for shielding and grounding:

IEEE 802.3

All shields of the individual signal and power pairs are connected to pin 4. The overall AUI cable shield is connected to the AUI connector shell to provide a cable ground. Pin 1 is not used.

Cable Pinouts C - 3

Page 223
Image 223
3Com 5102B-EE installation and operation guide Transceiver Cable Differences, Shielding and Grounding, Ieee