To exchange information between asset management software and a BAS, an application programming interface (API) is used. APIs can be accessed over networks, such as the Internet and company intranets. APIs also allow access to a remote system hosting the requested services. To do that, APIs often employ open database connectivity (ODBC), which provides a standard method for using database management systems (DBMS).
Many BAS manufacturers offer frameworks because they simplify programming. This means a facility executive transmitting real-time energy data to corporate accounting can focus on the specifics of energy use rather than the mechanics of request handling from the billing department, for example. No matter what protocol is used, the framework normalizes information and then formulates it into a common language.
In addition, frameworks can be expanded relatively easily. So if the CEO previously wanted only real-time energy data, but now wants to have the corporate carbon footprint on its homepage, the framework normally can be extended for this additional element.
Another way to interface between the BAS and integrated enterprise applications is to use intelligent middleware. Middleware is software that connects separate software applications and passes data back and forth. It is generally based on XML, SOAP, Web services and service-oriented architecture. In service-oriented architecture, the communication is a message, rather than an operation. Service-oriented architecture is good for providing such details as energy consumption so that CEOs can determine if partnering with the local utility for demand-side management is feasible, for example.
Here's one way to use middleware: Information from the BAS can be shared with the enterprise asset management system, so that the financial officer can budget when specific large pieces of equipment may need replacement based on their repair history.
How do vendors move data from intelligent devices to the link layer and then up to the application layer? The short answer is vendors are using Web services and Internet connections, with various combinations of open protocols, standards and proprietary solutions. In other words, each vendor accomplishes data exchange a little bit differently.
Here is a brief overview of how some industry vendors handle the task.
Alerton's software and hardware products come with built-in communication capabilities that rely on standard protocols and standards like TCP/IP and BACnet.
Automated Logic's primary data exchange with IT systems is via Web Services (XML/SOAP). The company's BAS functions as a Web services server. Automated Logic also publishes a list of function calls that IT systems use to extract data from virtually any point in the system. Alarm messages to an IT system are sent via SNMP trap.
Johnson Controls, Cisco, Schneider Electric Buildings Business (formerly TAC) and Delta Controls use intelligent middleware as one of several solutions that enable data sharing and control.
Other companies, such as Teletrol (now a Philips company), use an open information platform. Integration of building information with enterprise applications uses standard IT application methodologies, such as direct database access (e.g., ODBC compliant), standard report writers like Crystal Reports, or Web services. Crystal Reports is a business software application used to design and generate reports from various data sources.
Delta Controls also uses standards such as BACnet Web services and its own drivers to provide a programming interface between industry standard communication tools and the IT domain. On the other hand, Honeywell's asset management products are integrated with its own platform to provide integrated data delivery using standard technologies like HTML and XML.
IBM's solution uses service-oriented architecture methodology with Web services or OPC (open process connectivity) based integration.
Johnson Controls, Inc. and Schneider Electric Buildings also build data-sharing into BAS, so they can exchange information northbound to the enterprise and southbound back to the BAS.
KMC Controls software uses BACnet/IP protocols and OPC data acquisition. Reliable Controls offers a BACnet Web server. Using Microsoft Internet Explorer, operators can view and manually override setpoints, adjust schedules, print trend and runtime logs, and view and print current alarms. An audit trail allows tracking of user changes made over the Web.
Siemens Building Technologies BAS uses BACnet, LonTalk, Modbus and other common open protocols and standards for devices.
Tridium's framework technology is built into various BAS manufacturers' units, as well as being used in Tridium products. The framework doesn't care if the system is talking BACnet or LonTalk or a proprietary language.
Trend Control Systems uses intelligent field controllers that present data to workstations. XML support is built in, so workstations can collect and archive data accessible from enterprise software. Integration controllers support Trend proprietary data, as well as BACnet, LON, OPC servers and interfaces.
Advances in technology have made information more accessible than ever before. The diversity of methods in the industry can satisfy the information needs of most any kind of facility organization. Regardless of the methods chosen, the goal is the same: Link building and enterprise systems to manage the business most efficiently. 
Rita Tatum, a contributing editor for Building Operating Management, has more than 30 years of experience covering facility design and technology.
The most prevalent enterprise data currently being linked from BAS, according to the vendors interviewed, concerns current and historic energy and water consumption, particularly as it relates to carbon footprint; asset management, including operations and third-party preventative maintenance, fault detection and diagnostics programs; and into financial management programs to track and allocate costs by department or tenant. They often get this data through dashboards, spreadsheets and word processing software. — Rita Tatum
Making BAS And Enterprise Systems Work Together: Frameworks And Middleware
