Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: TUESDAY, September 26, 1995 TAG: 9509260009
SECTION: EXTRA PAGE: 3 EDITION: METRO
SOURCE: DAVID BUTLER
DATELINE: LENGTH: Medium
A: In personal computer lingo, a LAN (local area network) allows two or more computers to exchange data in an orderly fashion. It consists of cables and connectors, a network adapter card for each computer and software to tie it all together.
LonWorks is a special type of LAN. Its creator, Echelon Corporation, coined the term ``LON'' to mean local operating network. The distinction is subtle but important. A LAN is suited for exchanging large chunks of data. LANs are most often used for e-mail and for sharing unique or expensive resources such as a file server or color printer.
Echelon saw the need for a different type of network - one optimized for command and control rather than data transfer. When Echelon introduced LonWorks in 1990, the company touted it as a ``one-size-fits-all'' network for factory and building automation, avionics, automotive electronics as well as home automation. Already, LW has garnered widespread support among building and factory automation professionals.
The LonWorks protocol is a set of rules that allows products to communicate over various types of wire - mainly household electrical wiring and high-speed twisted pair. (Twisted pair, also known as bell wire, is similar to the low-voltage wire used to connect telephone jacks.) Any product with an LW interface can exchange pre-defined or custom messages with other LW products.
At recent trade shows, at least 20 companies demonstrated residential products in a mock-up of a home. Although most of the products were developed for energy management projects, three companies demonstrated LonWorks-compatible audio systems.
As with CEBus and X-10, LonWorks can operate over existing 120/240-volt AC wiring. This means no network connection other than a standard wall outlet. After a quick setup procedure, you're in business! Some products, especially those that don't rely on household current, will instead send messages over twisted pair. Each manufacturer must decide which type of interface to include.
LonWorks also supports wireless products (radio frequency and infrared). A LonWorks remote will be able to communicate directly with products throughout the house. The network automatically transfers messages onto the power line or twisted pair (using what's known as a router). One company is developing a bi-directional remote that would allow a user to quickly check the status of any product on the network.
The next few years will be a time of transition as manufacturers sort out their respective products' roles in the integrated home of the future. Not surprisingly, already-intelligent systems (e.g., security, whole-house audio and low-voltage controlled lighting) dominate the first generation of LonWorks products. LonWorks makes it possible for these and other home systems to collaborate, delivering benefits that none could provide independently.
LonWorks is getting a big boost from several electric utility projects. The largest involves more than fifty-thousand homes. Smart meters, thermostats, cable TV decoders and load control switches are among the products being adapted to use LonWorks. As the electric utility industry moves toward deregulation and competition, it promises to play a pivotal role in bringing home automation to consumers.
To receive a copy of my LonWorks Resource List, please send $1.50 and a self-addressed envelope to David Butler F-535, Department TWN, 14713 Pleasant Hill Road, Charlotte, N.C. 28278-7927. The list includes companies that have introduced or will soon introduce LonWorks-based products and wiring systems as well as a brief summary of the electric utility projects involving LonWorks.
TechTalk: The LonWorks protocol is embedded in a special chip called the Neuron. It contains three central proces
sing units (CPUs), several types of memory and extensive support for real-world inputs and outputs. Each chip is identified by a unique 48-bit digital code (more than 280 trillion possibilities!).
by CNB