3com 5101T-FB-ST User Manual

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. The V1.0 standard does not contain 
this requirement.

The three standards specify different techniques 
for shielding and grounding.

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.

All shields are connected to pin 1 and the AUI 
connector shell. Pin 4 is not used. Most Ethernet 
cables are built this way.