Owner`s manual

Page A-12 Appendix A
10Base-T Topology and Cabling
Ethernet networks were originally designed to be multi-point networks arranged as a
bus topology. That meant that Ethernet would work over coaxial cable (either thick or
thin) with 50 ohm termination at each end of the network, and each computer would
attach directly to the same cable.
With the introduction of 10Base-T, Ethernet can be connected via inexpensive twisted
pair (Level 5 compliant) cabling, with each computer having its own RJ-45 termination.
As a result however, the network topology is changed so that a central repeater or "hub"
is required to perform the task of re-broadcasting both data and Ethernet control signals
to all other computers connected to the Ethernet. Such repeaters are commonly
available from commercial sources.
10Base-T connections use 100 ohm un-shielded twisted pairs, with at least two pairs
per cable (one set of pairs for transmitting data and another for receiving). 10Base-T
cables terminate in eight pin RJ-45 connectors with the following pin assignments:
10Base-T (RJ-45) Connector Signals
RJ-45 pin no. Signal Name
1 Transmit Data +
2 Transmit Data -
3 Receive Data +
6 Receive Data -
The 10Base-T specification allows a maximum distance of 100m (approx. 300 feet)
between the computer and hub.
Ethernet is available for Eagle 100 computers as an optional feature, based on the
purchase of an AM-366 Ethernet Product Installation Kit.
Eagle Series Computer Owner’s Manual, Rev. 04