No Drop Cables Allowed from Thin Ethernet T-Connector to NIC

ID: Q93019

The information in this article applies to:

Microsoft Windows for Workgroups versions 3.1, 3.11

SUMMARY

The following configuration is not supported by 802.3 10BASE2 (Thin Ethernet) cable:


    tT ----RG58/u (Main Cable)-------------Tt
     |            |
     |<---RG58/u (Drop Cable) |
     |            |
    NIC               NIC

Key

t = terminator
T = T-connector
NIC = network interface card

The additional drop cable depicted in the above diagram should not be used. The T-connector should be connected directly to the network interface card.

MORE INFORMATION

Because Thin Ethernet network interface cards are not impedance matched, some of the signal coming off the main cable reflects off the network interface card and back on to the main cable.

If the distance is short (less than one to two inches), the echo lands right on top of the main signal and no distortion occurs.

If the distance is long (more than one to two inches), the time taken for the signal to travel down the drop cable, bounce off the card, and come back, is significant and can make the echo land on top of the next pulse, which can result in scrambled signals.

Additional query words: 3.10

Keywords :
Version : WINDOWS:3.1,3.11
Platform : WINDOWS
Issue type :