At either end of a bus is a terminator, which is essentially a resistor. The resistor is connected on the ends of the cable to provide a load for the circuits that attach to the bus in each node. You may have heard of a network not being properly terminated. This means the resistor is missing or has the wrong resistance.

The location where a node is connected to a bus is called a "tap." The most common way to connect to a bus is by a "T" connector, which attaches to the common cable. This connection is passive. Coaxial cables are used to form a bus topology.

A node on a bus communicates by broadcasting information that tells to whom the message is being sent. Every node on the bus "hears" every message. When a node "hears" a message addressed to it, it copies the message off the bus.

[ Previous Section ] [ Unit Contents ] [ Next Section ]