Five years ago, engineers dreamed about control systems from different control companies that could work together. There was no alternative to standalone control systems. Exasperated engineers routinely left the control system design to the control companies.

Then those unfulfilled dreams became reality as a new wave of technology enabled engineers to try to fill that control void. Since its introduction in the 1990s, the open protocol for building automation communications, called BACnet (Building Automation Control Network) has given building system integration a big boost. One recent publication has even listed BACnet among the top 125 innovations in the last 125 years.

BACnet became an ANSI standard, and the cycle of faster computers for less money enabled millions to gain proficiency in using computers. Other engineers, while mastering the new computer systems, suddenly woke up to find several small control companies with systems designed around the BACnet standard. Engineers improved their ability to design and specify control systems in a manner that enabled the forces of competitive bidding to actually be utilized in the control industry. They are now able to deliver robust control system designs that add fundamental value to any project they are used on.

Even large multinational control companies are closely monitoring the current trends of BACnet-only control system designs being employed throughout the United States. Once characterized as a fad by many in the industry, BACnet control systems are now being specified and installed on large numbers — if not most — of new building projects across the country. Automatic control systems are being used more effectively and in greater abundances on projects at lower costs and better long lasting value than ever before.

The Drive for Industry Acceptance

Ira Goldschmidt, P.E., senior engineer, RNL Design leads seminars for consultants across the country on specifying BACnet systems. He summarizes BACnet’s development and future thusly, “As an ANSI standards body, ASHRAE is bound by the rules of public review and comment. From the time of BACnet’s first published draft, it took four years, three public reviews, and the individual resolution of 741 comments to gain approval of formal publication of the standard in 1995. This process helped make BACnet stronger than any proprietary protocol could ever hope for, but delayed its release to the point where it could have died on the vine.”

Fortunately for the entire concept, many industry leaders were quick to recognize that the BACnet standard would be around for a while. Clair Jenkins, president, Alerton Controls Inc. put it this way: “As our industry, and Alerton in particular, embraces this significant and positive development in building automation, we look forward to serving our customers with even better choices and higher levels of quality facility management. BACnet opens the door to true systems integration.”

Gerry Hull, president of Automated Logic Corporation (ALC) indicates that “when we first took a look at incorporating BACnet into our control systems, we asked ourselves two fundamental questions. One, does it have ‘legs’ (meaning, will it be around for a while), and does it have fundamental value?’” Accurately assessing these two fundamental issues early on led ALC to develop BACnet products and establish themselves as leaders in the BACnet movement.

The completion of the BACnet standard also paved the way for interoperability. Manufacturers using the BACnet standard in their products started as a trickle in 1995 and is gathering considerable steam going into the new millennium. Mike Newman, chairman of the ASHRAE committee overseeing the BACnet standard says, “The ultimate success of BACnet depends on users specifying BACnet products and manufacturers delivering them.”

Figure 1. Definitions of a few helpful controls terms.

The Birth of Big-NA

However, the idea behind BACnet was always focused on the user first, and in response to that philosophy, BACnet interest groups have been forming across the globe, making it easier to get “unbiased” information on BACnet control systems. The BACnet Interest Group-North America ( proclaims its purpose on its website: “To facilitate the open exchange of user ideas and experiences as the complete interoperability of building systems is achieved.”

BACnet is becoming the de facto world standard as well. Before there was a BIG-NA there was a BIG-EU (BACnet Interest Group-European Union). Within months of BIG-NA’s formation, BIG-OZ (BIG-Australia) began forming. BACnet interest groups are coalescing in Japan and South Africa. It seems that BACnet is transcending language, cultural, and economic trading barriers at an astonishing pace. On September 30, 1998, ten colleges and universities plus several engineering consultants were represented at a BACnet symposium hosted by the University of Cincinnati. “It was like walking out of Independence Hall this morning!” declared Mike Newman as he began his presentation in the General Session. “Independence Hall” referred to a breakfast meeting with some of the delegates where the first plans for a BACnet interest group were summarized. The entire symposium started out as an educational session, but it now appears that its most lasting impact will be the genesis of the interest group to support and promote the use of BACnet building control technology.

The college and university users in attendance were concerned about what had traditionally been a vendor-driven market. They realized if they banded together, they would have the opportunity and the market clout to help turn the industry around to become a user-driven market. They have concluded that BACnet technology is the tool they need to achieve this goal.

A few months after the Cincinnati meeting, BIG-NA was formed. BIG-NA was the first to establish a presence on the Internet. Links to and from other BACnet and building automation sites enable even the novice to obtain the most current information on the BACnet communications protocol and its impact on the building industry.

On September 21, 1999 BIG-NA had its first official fall meeting at Purdue University (West Lafayette, IN). The meeting was similar in many respects to the Cincinnati symposium. Association rules were openly discussed, revised, then immediately posted to the website for users everywhere to read. Summaries from BACnet vendor presentations were posted to the website even as they spoke!

The power of the Internet was illustrated by the presence Masanori Onishi (from Japan). Onishi is deputy general manager for Tokimec, Inc., and he learned of the conference via the advertisements on the BIG-NA website.

OBIWAN: Using the Force of the Internet

In less than a year since its startup, BIG-NA has launched a bold new project named OBIWAN — the Open BACnet Interoperable Wide Area Network (called O-B-1 for short). This project demonstrates different control systems in action, working together over the Internet, through standard web browsers. OBIWAN is designed to demonstrate that BACnet is truly the “Force of the New Millennium.”

OBIWAN had its genesis inside a chat area of BIG-NA’s website. Joel Bender, a senior programmer and analyst in the utilities department for Cornell University, started it off. “I’ve been tossing around an idea and I thought it might make for a good discussion. How about putting together a BACnet Internet of devices that are publicly available? I would like to display a graphic on my computer of real-time outside air temps from every BIG-NA member organization on a map of North America. With BACnet/IP now a part of the standard, ‘we’ could pull this off … So does it have enough coolness factor? What kinds of data besides meterological points do you think could be provided? How about real-time natural gas prices? :-).” The Purdue conference provided a lot of peer interaction that helped fuel the growing momentum behind OBIWAN. Ten core group participants were identified to help launch the first BACnet/IP network of devices to be accessible to BIG-NA members through The website will link together OBIWAN deployment sites from all over the world via the Internet. The rollout date planned for OBIWAN is February 7, at the ASHRAE/Dallas 2000 meeting.

OBIWAN is a BACnet/IP internetwork of devices that is accessible to anyone with an IP connection. The mission is to dispel any misinformation about the scalability or interoperability of BACnet devices by providing real products online. Anyone can make equipment available to OBIWAN. Because of the network topology restrictions of the current version of BACnet, some portions of OBIWAN will be centrally administered by BIG-NA.

The OBIWAN backbone consists of a group of network devices that provide routing for BACnet broadcast messages, foreign device registration, and routing to non-IP LANs. The simplest way for an institution or vendor to join OBIWAN is to install a BACnet Broadcast Management Device (BMMD) on their LAN. They must provide its IP address to the central administration and accept a list of cooperative BBMDs (accept a Write-Broadcast-Distribution-Table message).

Initially, core group participants are asked to display one temperature sensor at their deployment site. The sensor values will be displayed on the BIG-NA website using Java Applets. (Java is an object oriented programming language created by Sun Microsystems. Applets are small Java applications that download via the Internet to client computers.)

Interactive Java applets are already being used on, which enable core group members to dynamically view and mark-up the growing OBIWAN control schematic. Core group members have Java routines to display the temperature sensor reading for the initial rollout of OBIWAN. Once connections to all sites are accomplished and troubleshooting is over, individual sites will add additional devices of their own choosing. Software to participate in OBIWAN will be available through BACnet Open Source Solutions (BOSS).

BOSS is a collection of open source (GPL or BSD licenses) software available for the Macintosh, Linux, VAX/VMS and Windows platforms. During the first couple years of the new millennium, through BOSS and BIG-NA, facility managers will realize a whole new realm of Internet accessibility to their building automation systems. Facility management (FM) extranets are already being set up by forward-looking engineering consultants as a logical extension of project extranets presently in use to facilitate communication of design and construction projects. The new FM sites will provide users with unprecedented options to facility information, all via secure scalable connections.

BIG-NA’s OBIWAN is designed to grow and maintain a strong presence for the next several years. It will be a place where building owners and managers can go over the Internet to see real BACnet products interoperating with each other. It will be a place where vendors can show off their products to eager audiences. Through trial and error, it will be a great learning experience for all involved. All activity will also be logged by users and for users using the various dynamic features available on the BIG-NA website. BACnet has enabled building automation control systems to keep in step with the fast-paced world of telecommunications and the Internet. This is the exciting aspect of OBIWAN is its demonstration of BACnet/IP, the accessibility to real-time direct digital control values from devices manufactured by different vendors which are still able to interoperate.

To Hvac and Beyond…

Regis Cleary, P.E., Senior Mechanical Engineer consultant in Central City, PA and an Interim Board of Director for the BIG-NA says if you want to know BACnet’s future, look at its past.

“If you want to know the future, look at the past. In the early 1980s, Apple Computer had a clear technical lead in personal computers, and IBM, while not a technical leader in PCs, had even greater name recognition. However, Apple and IBM lost their lofty market positions to PC clone makers because an operating system (both software and hardware) was available for use by many competitors. Intense competition among many rivals fostered rapid innovation. The cost of computing power plummeted. Even more markets opened as computers became both more powerful and more affordable.

“Ten years ago the world witnessed the fall of the Berlin wall. East Germans risked life and limb to pull down the wall. A throng of people rushed the gates to gain political freedom. The analogy can be made that existing BAS users were constrained people crashing the automation gateways, seeking market freedom. “As we close out one millennium and embark on another, those in the BAS industry contend with two rival philosophies. While the ‘Apples’ and ‘IBMs’ of the industry promote closed, proprietary standards, a group of smaller “innovators” are embracing the open, Internet-compatible, BACnet standard. In the Age of the Internet, you do not have to be a prophet to know which standard will come to dominate building automation systems.

“The significance of BACnet is not that it has become the dominant building automation control standard,” he continues. “Look for it to become the dominant apparatus control standard. Your coffee pot, your garage door opener, your dishwasher, as well as your furnace, electric meter, room air conditioner, lighting, security, and fire alarm will be controlled using BACnet. An individual with a cell phone and the proper security code access will be able to remotely control and monitor just about anything that uses electricity. The translator that will allow all of these machines to communicate will be BACnet because BACnet uses the language of the Internet; sending e-mail to an Internet address is not technically different from sending a message to a thermostat that also has an Internet address.”

In the meantime, the technology’s backers are settling for finding new ways to demonstrate to building users and owners that BACnet adds fundamental value to vendors’ products and, most importantly, to the building itself. ES