Overview

Some computers are independent units, with little need to exchange information with other computers near or far. At most, these computers may use local interfaces such as USB or RS-232 to communicate with printers or other devices close at hand.

But with a network connection, a computer can reach beyond its local interfaces to send and receive information of any kind, over distances large and small, via wires or through the air. Computers of different types can communicate using network protocols supported by all. In a network of embedded systems, each system can communicate with the other systems in the network, sharing information and sending and responding to requests as needed. Desktop computers in the network can monitor and control the operation of the embedded systems.

Many local networks follow the networking standard popularly known as Ethernet. Ethernet networks are capable and flexible. Many products designed for use in networks have support for Ethernet built in. A router, or gateway, enables an Ethernet network to communicate with computers in other networks, including computers on the Internet.

Two or more computers that share a network connection form a local area network, or LAN. The smallest network links just two computers. For example, a data logger might connect to a remote computer that receives and displays the logger s data. Or a personal computer (PC) may use a network connection to monitor and control a piece of equipment. At the other extreme, the Internet is the largest network. With an Internet connection,...