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Converging BAS With IT Architecture

March 1, 2008
Building-automation systems (BAS) have made strides toward embracing connectivity and interoperability standards in recent years. These efforts have given

Building-automation systems (BAS) have made strides toward embracing connectivity and interoperability standards in recent years. These efforts have given building owners more freedom to choose among manufacturers for products and service support. Benefits await organizations that have merged their BAS and information-technology (IT) architecture. The synergy created by sharing infrastructure and data reduces operating costs and creates new service opportunities.


Convergence in BAS terms is defined as the complete integration of building systems with the larger IT systems and connected enterprise applications that exist within most buildings — or, on a global basis, a group of networked facilities. An important distinction is that while there has been connectivity between these disparate systems, integration has not necessarily existed. Different systems and applications can communicate basic information, but they usually lack complete data-exchange capabilities.

With true convergence, we are empowered to obtain more information on a by-request basis and in a manner that is more easily understood by any technology system within a building and those who want to analyze the information. This elevated level of integration opens new avenues that were not technically or economically feasible in the past. One example of this integration includes sending a text message to the energy manager of a health-care campus to alert him of a potential peak in electrical usage. The information is compiled and interpreted at the BAS, travels across the IT-network backbone, is sent by the enterprise server across the Internet, and is delivered via a cell-phone network.

In this new environment, BAS are less expensive to install because they can use the existing IT infrastructure. High performance levels can be achieved more economically because a single high-speed network avoids the redundancy that is required with a separate BAS infrastructure. Furthermore, with fewer wires, bridges, routers, and repeaters throughout a building, there is less propensity for component failure and downtime.


Many in the BAS industry believed, perhaps naively, that simply enabling BAS to deliver information via Web pages would allow those data to be among the services delivered across enterprises for varied applications. As a result, early implementations of BAS workstations delivered across the Web often were disappointing.

While that was true in the past, it is time for the BAS industry to seize the opportunity that convergence presents. This involves fully understanding the IT infrastructure and cooperating with those who implement the network for the enterprise. It also is important to recognize what motivates an IT department when teamed with a facility staff so that both disciplines work together efficiently.

Clearly, convergence depends on the successful integration of building controls. Therefore, when a BAS device is to be added to an IT infrastructure, a document that describes, in the IT staff's language, precisely what is being added to the shared network and what effect the device will have on the network must be developed. The result will be a system that reflects the needs of both departments.


Convergence creates opportunities for information systems and the people who manage those systems. Collectively, these opportunities are known as “divergence.” For example, to prevent equipment failure, facility professionals could learn an IT department's approach to maintaining network-control devices. After all, facility and IT equipment share the same network underpinning, so why should they not be similar in terms of maintenance? (Although a chiller and data server are not alike, a networked chiller controller has a lot in common with the personal computer used to enter and access data.)

Divergence requires new skills for the building-automation profession. This is challenging because the skills of building managers and technical staff are an accumulation of what these people have learned over many years. Now that more diverse technologies and methods are available to operate and maintain building systems, the possibilities have expanded.

Keeping pace with this potential will require facility experts to broaden their knowledge bases. They will need to attend different types of seminars, explore different courses of instruction and, in general, rethink the status quo. They must borrow best practices from IT professionals who have had these opportunities all along.

Building-systems engineers should have no fears about their profession diminishing in the future of the enterprise-connected building. This is because they are domain experts who have the knowledge to design properly functioning building systems. They simply need to realize that the landscape around them is changing and that they must adapt accordingly.


Since the 1970s, BAS components have been designed as part of mechanical- and electrical-system infrastructures. Components below the workstation level have had to be rugged enough to reside in equipment rooms, yet also include a communications interface. It now is just as important for all devices that connect to an IT infrastructure to be good network citizens as it is for them to endure harsh environments. This citizenship takes many forms.

Communication protocols

BAS manufacturers have accelerated the rate of open-protocol-device development to BACnet and/or LonWorks interoperability. In the world of convergence, systems that claim to provide interoperability and conform to industry standards must provide connectivity to a variety of equipment that integrates seamlessly into a network. Neither BACnet nor LonWorks alone provides complete total-enterprise information compatibility. A better solution is to apply the new standards for interoperability, such as eXtensible Markup Language- (XML-) based communications applications, to achieve all of the benefits that each protocol offers. In general, systems that require interoperability on a broad basis will be served best if they support multiple protocols. It always is good practice to keep interoperability options open.

It is beyond many people's experience base to be concerned about network-management considerations. This is the point at which strict adherence to IT standards is critical to the success of convergence. Following is a review of standard network protocols and languages:

  • XML is the universal language of Internet data exchange and can be called across platforms and operating systems regardless of programming language. XML is the basis for a new form of system interoperability that relies on Web Services. These are small, reusable applications that handle all communications between otherwise disparate devices or applications. Web Services are designed to support interoperable machine-to-machine interaction, such as between computers and between software applications, over a network.

  • Simple Network Management Protocol (SNMP) compatibility is a must for BAS devices because it allows an IT department to use its network-management software to check the status and operation of network-connected equipment. SNMP-enabled supervisory engines can report alarms or warnings based on memory usage, processor temperature, or other critical operating attributes of the hardware or software.

  • Simple Network Time Protocol (SNTP) or Network Time Protocol (NTP) provides the standard method used to synchronize time between a designated time server and BAS devices. Historical-data functions and scheduling elements are impacted. Imagine the difficulty of scheduling energy usage in a school or office without synchronizing with the rest of the network.

  • Simple Mail Transfer Protocol (SMTP) support is required so messages from supervisory devices can be transmitted using standard e-mail. This feature is important because using Internet-client devices instead of workstations for operation means that alarm-reporting software may not always be online. Pagers and e-mail must substitute for dedicated alarm annunciation. One problem is that many virus attacks are spread via incoming e-mail. System designers must take care if messages need to be received.

  • Simple Object Access Protocol (SOAP) is the most common transport mechanism for XML. SOAP rides on the Industrial Protocol (IP) network.

  • Hypertext Transfer Protocol (HTTP) is the vehicle for most Web-browser-based communications and requires an IP network for BAS implementation.

There are more protocols and languages that may be utilized within a networked environment, but the point is you do not want to be saddled with a proprietary solution if a standard exists.

Security is another major concern in this world of hackers, virus attacks, and spam. It is important to have system components that leverage the security efforts of an IT department. At a minimum, this means that BAS devices must behave in the presence of antivirus software and accept an authentication scheme that is compatible with the network. Also, it means that BAS servers and network-connected controllers (engines) operate through firewalls in an efficient and secure manner. Most IT departments are hesitant to open additional ports for these systems.

Operating systems

Standard operating systems are essential in a converged environment. Manufacturers must give up their proprietary, industry-specific operating systems and embrace IT-computing standards. This is necessary to set a firm foundation for the other IT standards that support enterprise-application integration and project-development tools. These are needed to better deliver the benefits and efficiencies of integrated operation. BAS suppliers do not add value by creating and maintaining their own operating systems.

There is no magic solution, but Microsoft has the most universal set of operating systems applied to the largest set of end devices on a global basis. However, it is possible to apply Linux, Sun Solaris, or Mac OS to the same tasks if there is an idea of what tasks must be accomplished and to which devices these tasks and applications will be applied.

Web-server technology

In virtually all cases, it is desirable to use an organization's standard Internet browser as the user interface for a BAS. A Web solution that requires a dedicated workstation (sometimes disguised as a server) is not delivering on the vision of networked computing. This requires a change in basic network architecture, as shown in Figure 1.

A building-level supervisory controller must be replaced with an IT-enhanced engine because there is no workstation in the new system's architecture. Therefore, the supervisory controller must accept additional responsibility as a user interface, data server, and programming-tool repository. Taking this concept one step further, IP-connected control engines combine advanced control technology with the supervisory functions of an IT-enhanced engine. They are best suited for applications in which large central plants or complex control strategies demand more processing power and additional memory for historical data.

It is not difficult to accomplish these tasks, but it can be challenging to accomplish them in a manner that gives users easy access to enterprise computing applications. Providing easy-to-learn and use tools for the programming and commissioning of such devices is an even greater task. Systems that require integration professionals or advanced users to write HTML pages to access information meet the intent of convergence, but do not deliver the functions required to satisfy end-user needs.

As a rule of thumb, make everything accessible to the Internet or corporate intranet as much as possible, while keeping security needs in mind. Use the latest and best networking and server technology, and make sure that the system communications are compliant with standards.


With changing requirements for communications and infrastructure compatibility, hardware must change fundamentally. Table 1 highlights methods and equipment BAS developers have employed in the past, current requirements, and a vision for the future. New hardware must support this functionality and drop seamlessly into the IT network used by an enterprise.


Equipment monitoring

There are two fundamental reasons to monitor equipment. One is to alert the operator in the event of a failure or potential failure; the other is to gather data to evaluate maintenance and operational effectiveness. Because a converged system is more capable of communicating with more devices and exchanging data with other applications across an enterprise, both of these functions can be improved and expanded.

Environmental and energy reporting

Just as equipment monitoring provides information vital to operation, it is necessary for environmental and energy-consumption information within a single building or campus to be communicated effectively.

In the past, there often was a disconnect between the data collected by a BAS and the information required by an owner's representative to model and control energy usage effectively. The ability to access and communicate real-time and historical data between energy-using end devices and environmental-monitoring devices (BAS) — as well as enterprise computing applications — had not kept pace with other IT developments.

Convergence provides the pipeline to deliver this information anywhere at anytime by using Web technologies as the delivery mechanism and avoiding the use of dedicated workstations that confine users to a chair in a control room or office.

Alarm transmission

The purpose of an alarm is notification. If an alarm sounds in an unmanned control room with nobody to hear it, then no alarming function is being performed. In this era of mobile work environments and multiple task assignments, it is important for alarms to track the intended recipient.

As mentioned previously, an alarm can interface with an IT network and ultimately be communicated via cell phone. The application of network-communication capabilities in a converged environment enables the inclusion of pagers, wireless laptops, personal digital assistants (PDAs), and other multimedia-enhanced personal devices. Information can be communicated and shared with individuals or groups across the globe. Those individuals can find a computer terminal or Wi-Fi hot spot to get additional information about an alarm they have received.

Database sharing

Until now, databases have been purpose-built for BAS or industrial control systems. It was not easy to merge this information into databases that reside elsewhere in an organization. However, if data are stored in a standard Oracle or Microsoft SQL database structure, it can be exchanged easily throughout the enterprise. For example, you may use an energy-consumption database to estimate next month's energy bill, merge this information from your financial database into enterprise databases so other departments can forecast their budgets more accurately, and print a report that identifies the resultant enterprise expenditures.

Equipment time sharing

When all building systems are interconnected and can speak the same language, it is possible for computers and devices to serve multiple purposes. For example, a video camera can be used for more than security. That camera also can monitor a device that indicates whether a sump is high or low. A small box in the corner of the device will display a raised flag if a problem in the sump needs attention. Monitoring this via the camera eliminates the need for personal inspection, increasing employee productivity.

Occupancy sensors that turn on lights could be synchronized with a security system. These sensors also could be used for air quality by alerting an air-handling system to pump the right amount of air into an occupied building at the right time. Further, using these sensors could determine whether a particular area within a facility is using too much energy based on its occupancy.

Remote access

As noted previously, we live in a mobile world. People do not want to be tied to a single location to do their jobs, much less a chair in front of a computer. Global professionals require access to information without contacting another person or traveling to a fixed location.

The current Web infrastructure in most countries provides just such a connection, as long as the system converges with it at the source. Connecting a computer to the Web with a cell phone, wirelessly accessing a PDA to the network in a hotel, or walking into an Internet cafe on a cruise ship gives anyone access to this capability. Systems providers must ensure a capable and straightforward user interface to leverage these capabilities.


Web Services and interoperability

The convergence of building-control and IT infrastructures will pay its biggest dividends in Web Services. The Web Services model provides data to diverse requestors of information. This opens the floodgates for a new class of information-rich applications to be delivered anywhere at anytime across a network. It is accepted that initial delivery of these services will be accomplished over the Internet or corporate intranets via a combination of XML and SOAP. XML is a common model for data representation; SOAP is used for communication.

The immediate goal for industry leaders is to define services and objects that the XML and SOAP communications standards can request and deliver regardless of the originating systems or protocols inherent to their basic operation. This will answer a common question: Will it be necessary for all systems in an enterprise to use the same BAS protocol to provide information to a client? The answer is no. As long as each system can handle data and respond to a request for information, it does not matter how the information got there. BACnet, LonWorks, ModBus, or any proprietary protocol are equal service providers in the eyes of an XML/SOAP-empowered client. Web Services will not be a substitute for interoperability at the control level or the accuracy and dependability of individual controllers.

What we have when building-control and IT infrastructures converge is a fully Web-enabled system that bridges the gap between these infrastructures within an enterprise. The system will deliver information-rich database applications that are transportable between standard hardware and software platforms. It will be expandable and extendable using protocols and hardware that have been proved.

The ability to use Web Services as a tool for the analysis, control, and prediction of energy usage is enhanced by a standard means of defining XML data so that BAS and energy-consuming-device vendors all conform. Using Web Services in this manner simplifies the task of integrating this information.

The array of services that can be provided is a powerful motivator toward the implementation of a fully converged BAS/IT infrastructure. These services include:

  • Energy-accounting services, which allow each building to report data to a common repository.

  • Air-quality services, which enable indoor-air quality from large multisite locations to be analyzed in light of geographic and meteorological factors.

  • Other services that can compare the efficiency of mechanical and electrical equipment with benchmarks.

Web Services are just beginning to have an impact in leveraging this convergence. In the future, a college professor who wants to use energy and air-quality data in a case study will be able to do so easily. Today, the professor may be hesitant to ask for information that would require many hours for a college-facilities staff to extract.

Wireless communications

A common feature of today's IT infrastructure is the in-building wireless distributed-antenna system. The basic infrastructure is a system of cables, antennas, and other components engineered to capture and convey signals throughout a building and confine them to the interior. When added to a wired infrastructure, they can help building occupants tap the full power of current and future wireless services and applications.

The goal is to employ an in-building wireless distribution system that provides complete wireless coverage for a full range of voice and data services. Once a wireless distributed-antenna system is installed, it can be modified and expanded without intrusive, costly infrastructure changes. A well-engineered system helps eliminate dead signal spots and facilitates the expanding number of wireless applications and devices. These include wireless local-area networks, personal communications services, cell phones, PDAs, pagers, and two-way radios for maintenance and security. Such a system also enables wireless building automation in conjunction with a state-of-the-art BAS. A wireless infrastructure will help a BAS access data from multiple enterprise applications and assimilate it into meaningful information that helps managers operate buildings more efficiently.

This technology will help seamlessly and cost-effectively integrate fire and security systems and other building controls, whether they are in one building or spread across a corporate campus. As momentum builds, wireless distribution technology will become an integral part of a facility's infrastructure, providing building owners with solutions that simplify operations, reduce costs, and improve efficiencies. For example, a new Chicago-area children's hospital uses this technology to improve access to patient medical information through PDAs and other handheld devices. A doctor can check a patient's vital signs without reporting to the bedside. Hospital employees can read e-mail without having to stop at their desks. These are just two of the many productivity enhancements that a wireless distribution system offers.


In a perfect world, an organization's BAS and IT architecture would be a seamless entity. They would work in concert because they would share resources and adhere to the same set of standards. This scenario would offer many benefits, including:

  • Reduced management and infrastructure-equipment costs.

  • Critical building-system information being readily available at all levels of an enterprise.

  • Employees being able to access and act upon information without the constraints of a dedicated workstation at a fixed location.

  • The possibility of new services that save time and preserve resources.

When making an investment in BAS technology, an organization should look beyond today's configuration. Decision makers need to recognize the advantages of merging a BAS into an IT infrastructure. The technology platform selected to harness energy and operational data must be fully compatible with the IT network that already is in place. Allow a BAS to rely on an IT network as the data highway for safe and reliable transportation of information. In return, an IT staff will provide critical services for planning and maintenance.

Terry Hoffmann is the director of marketing for building-automation systems for Johnson Controls Inc. An adjunct professor for the Milwaukee School of Engineering (MSOE), he has a bachelor's degree in electrical engineering from Marquette University and a master's degree in engineering management from the MSOE.