For the usually slow moving building automation industry, the latest XML (extensible markup language)/Web services movement has been a bit of a blur, spawning a number of dot coms and dot orgs to share information with our industry. The purpose of this article is to provide you history, connection, and insight into these valuable resources.

In The Beginning, There Was An Idea

I first heard about XML/Web services at the 2001 AHR Expo in Atlanta in a brief meeting with Eric Craton and Steve Tom of Automated Logic, held in the hallway of the convention center. Craton explained his vision of how Web services would change everything. I can still see the excitement in his eyes.

As I grasped what he was talking about, my excitement also started to build. Craton warned me that all this stuff was pretty bleeding edge, and that many conventions needed to be established by the IT industry to make it really useful. Automated Logic's early entry into Web-based control with a full Java platform allowed them to provide a strong lead in how Web services might unfold. In January 2002, Craton helped me create a Web services forum on the website.

Here is an excerpt of an article, titled "Information Model: The Key to Integration" by Craton and Dave Robin (also with Automated Logic), which provided the cornerstone of our Web services forum ( "What is the future of Web services in building automation? Let's look at the four trends in terms of Web services:

  • Content is becoming dynamic. A Web service has to be able to combine content from many different sources. That may include furniture inventories, maintenance schedules and workorders, energy consumption and forecasts, as well as traditional building automation information.
  • Bandwidth is getting cheaper. A Web service can now deliver types of content (streaming video or audio, for example) that was unthinkable a few years ago. As bandwidth continues to grow, Web services must adapt to new content types.
  • Storage is getting cheaper. A Web service must be able to deal with massive amounts of data intelligently. That means using technologies such as database replication, LDAP directories, caches, and load balancing software to make sure that scalability isn't an issue.
  • Enterprise computing is becoming more important. A Web service can't require that users run a traditional browser on some version of Windows. Web services have to serve all sorts of devices, platforms, and browser types, delivering content over a wide variety of connection types for a wide variety of purposes.

"The hypertext markup language (HTML) format was designed for webpages to be read by humans. Like a universal word processor format, HTML combines text, pictures, and formatting information so a browser can display it on a screen. HTML is not adequate for information exchange between computers, however, because it provides no information about the data that may be contained on the screen and no way to search for specific pieces of data. For Web services to address all of these needs, two other, more flexible technologies are crucial:

  • XML - XML is a technology for moving structured data across the Web or a corporate network. Like the object-oriented protocols described previously, XML documents include more than just raw data. An XML document includes a definition of the data structure, so the receiving computer knows what information is contained in which fields.
  • SOAP (simple object access protocol) - While XML is basically a file format, SOAP is a way of using XML over a network. SOAP provides a computer application with a tool that can read the data definitions in an XML document and extract the required data. SOAP is to XML what hypertext transfer protocol (HTTP) is to HTML.

"All of the major enterprise software vendors are fielding products and platforms that support the Web services architecture using XML and SOAP, including Microsoft.NET, IBM WebSphere, Sun Microsystems SunOne, Hewlett Packard Web services platform, Oracle 9i, and BEA Systems WebLogic, among others."

New Groups And Allies

This blueprint for the industry was a harbinger of change, and at the 2002 AHR Expo in Atlantic City, I met with Paul Ehrlich of Trane. Ehrlich explained his vision for his company of building product based on Web services and how industry standards were required for this to happen. Committees and organizations, larger than the present industry, would be required.

My optimistic goal was to have a Web services XML demonstration for the Chicago AHR Expo. This did not happen, although much progress was made and a committee was formed with Ehrlich as the chairman. The politics of which industry organization this committee should belong to was amazing. The Web services concept was much larger than all of our traditional organizations, as it involved many other industries such as lighting, security, etc., as well as the IT industry.

Ehrlich and his committee chose to work with the Continental Automated Buildings Association (CABA, CABA is a not-for-profit industry association that promotes advanced technologies for the automation of homes and buildings in North America. One of their objectives is to facilitate and encourage industry-wide interoperability of protocols and standards. CABA provided shelter from the political storm by providing a non-HVAC organization that crossed over several major related industries such as lighting and security, but still had a strong connection to ASHRAE.

The committee evolved well in this transition space and created the "Guideline for XML/Web Services for Building Control" (, the industry's first:

"The building controls industry has made great strides over the last 10 years in the creation of communications standards. Both BACnet and LonTalk are now viable, commercially accepted solutions that provide owners with open communications. Yet while we have made great progress in these areas as an industry, there has been an emergence of a larger, more globally accepted standard created by the world of information technology. In particular, the broad acceptance and ever lowering cost of Ethernet/TCP/IP/XML communications is finding its way into the industry. Owners today are looking for:

  • Building controls to utilize the infrastructure of their existing intranets and Internet;
  • Controls as a data source to help them better run their business; and
  • Systems that follow the same standards as other IS and IT devices.

And Then There Was Builconn

On my website, I posted an open letter from CABA to the building controls industry regarding a meeting that was held at BuilConn for the formation of open standards for XML and Web services ( It read in part:

"I attended this meeting and was amazed at the interest of the audience, plus the depth of industries represented. The meeting had not only great physical attendance but also a good representation by conference call. The complete group got it; moving ahead in today's market is going to require working as a team. The committee was given a clear vote of confidence to keep moving ahead as fast as possible. It was clear that all industries were using XML and Web services, and all agreed that guidelines were required."

Ehrlich's presentation from that meeting can be downloaded from The minutes of the history-making event are available at

Why was it done at BuilConn? It was the only event focused on integrated and networked building systems for contractors, dealers, and systems integrators.

oBIX Evolves

For those who don't know what oBIX is, it is the new identity for the work being done by the CABA-initiated XML/Web Services Committee and stands for open building information exchange. The group initially met last April during BuilConn and met again last June during Realcomm in Chicago. This group is now one year old and has been christened with the name oBIX. Legally speaking, oBIX is the name of the resultant work.

oBIX is a focused effort by industry leaders and associations working toward creating a standard XML and Web services guideline to facilitate the exchange of information between intelligent buildings, enable enterprise application integration, and bring forth true systems integration. Based on standards widely used by the IT industry, the oBIX guideline will improve operational effectivenes, giving facility managers and building owners increased knowledge and control of their properties. Comprised of representatives from the entire spectrum of the buildings systems industry, oBIX includes professionals from the security, HVAC, building automation, open protocol, and IT disciplines.

oBIX formed in April 2003 as the CABA XML/Web Services Guideline Committee. Since then, oBIX has taken on a life of its own with an expanded mission and increased visibility. For more information on the current status of this committee, visit

Keith E. Gipson, CEO and CTO of Impact Facility Solutions, provided more insight in this report from the BIG-NA conference. BACnet, IT, and XML are hot items. (

"This is where XML comes in. XML is a machine-to-machine, communication protocol that is in use by many non-HVAC vendors today. Lots of good work has already been done by ASHRAE and the building controls industry at large, and XML will not replace BACnet. However, what's needed right away are XML/Web services functionality. There is a committee that met during the BIG-NA conference called oBIX . The oBIX committee has a goal to move fast to create a non-binding guideline for the implementation of Internet standards for interoperable enterprise facility management.

"In conclusion, what is XML? XML is the easiest, fastest, and best way for vendors to expose extended functionality in their building controls systems. There may be a whole ‘laundry list' of functions that could eventually be developed, there are many different syntactical considerations, but start off by giving us all the ‘GetPointData' Web service. There are many people out there who are ready to put it to good use, for the benefit of their customers."

In a December e-mail interview I conducted with Ehrlich titled, "What is oBIX?" (, where he provided insight to this new organization.

Sinclair: What is oBIX?

Ehrlich: oBIX stands for open building information exchange, and it is an industry-wide initiative to define XML- and Web services-based mechanisms to present building systems-related information on TCP/IP networks such as the Internet.

Sinclair: Why is oBIX important?

Ehrlich: The IT industry is adopting XML and Web services as a critical technology for connectivity on the Internet as well as on corporate networks. Many significant industries that desire to leverage the Internet are also adopting XML and Web services as a platform for exchanging information. While the decision of adopting XML/Web services is a no-brainer, doing so without defining schemas and other cooperation standards does little to enable integration and interoperation in the building industry. oBIX is working to define such a mechanism specifically for the building systems industry.

Sinclair: In a nutshell, what is XML?

Ehrlich: Let's start with HTML. HTML is an Internet protocol all about controlling the display of information on Web pages, such as this article. HTML deals with the size of text, font, color, display of pictures, as well as hyperlinks. In contrast, XML is a protocol about raw data. It does not concern itself with display attributes, so a piece of XML information would simply say that a temperature is 72°F. It will be up to the recipient to decide what to do with that data. This makes XML ideally suitable for machine-to-machine communication, whereas HTML suits machine-to-human.

Sinclair: How does oBIX relate to CABA?

Ehrlich: CABA was instrumental in creating a committee in April 2003 at BuilConn in Dallas, and this committee - the XML/Web Services Guideline Committee - started the work that is now known as oBIX. CABA is the host of oBIX, meaning that CABA facilitates the work of the oBIX group, provides some services, and generally nurtures the group's activities in the industry.

Sinclair: To what extent will this impact the HVAC industry?

Ehrlich: XML and oBIX will have a very significant effect on HVAC, especially in how HVAC systems are integrated with other systems, into the rest of the building systems, and, more importantly, with the enterprise systems. Without oBIX, these tasks are difficult to do. With oBIX and assuming the proliferation of XML, these tasks become very easy. Integrators will be able to create richer cross-systems and cross discipline websites to satisfy users' needs.

Sinclair: How can I be involved with oBIX?

Ehrlich: Visit the oBIX website ( ) and join the bulletin board for discussions on oBIX. To be more involved, join one of the task groups. Contact information is provided on the website.

XML and ASHRAE: A Partnership In The Making

The first ever XML symposium was held this past January at the Anaheim Hilton Hotel during the AHR Expo. It was an eye-opener for all involved.

"As possibly the ultimate integration mechanism for buildings, XML will revolutionize the buildings industry," Ron Zimmer, CABA president and CEO, said. "This symposium will provide the HVAC professional with ample XML and Web services education and a practical expectation of their adoption rate within the industry."

What does the future hold? At press time, I am planning for BuilConn 2004. The XML Pavilion at BuilConn is a key element in developing the market's understanding of XML and Web services. The pavilion, a part of the Expo at BuilConn, will consist of approximately a dozen companies that are actively working on XML and Web services products and solutions. They will plug their prototypes or finished products into the Internet, and show BuilConn attendees how XML actually works. We are excited about what this year's BuilConn will uncover, as we all explore how to enter the enterprise gracefully and see the next chapter of XML/Web services oBIX unfold.

We will be continuing to inform you of the evolution of XML/Web services and bring you the summary of the next chapter as it unfolds at the BuilConn event in our August ES supplement titled "Connecting Convergence." ES