For more than a decade, many in the buildings industry have been envisioning a day when building-automation systems (BAS) would become fully integrated with communication and human-interface practices and standards widely employed for information-technology (IT) networks. With the number of those individuals growing and their dream coming closer to reality, HPAC Engineering developed a five-question survey with the intent of gathering the varying perspectives of a control-system designer, a controls manufacturer, a controls integrator, and an advanced controls user (see sidebar, at bottom of article) on practices becoming increasingly common in development BAS. Following are the questions and the responses they elicited.

1. In this age of universal graphical user interfaces (GUI), is there any reason to continue using a BAS manufacturer's graphics instead of Web-browser-type operator interfaces?

“In general, no,” the survey's designer participant, Valentine A. Lehr, PE, FASHRAE, a senior partner of New York-based Lehr Consultants International and a member of HPAC Engineering's Editorial Advisory Board, said.“There is no reason for the manufacturer's graphics.”

The survey's advanced-user participant, H. Michael Newman, manager of the Utilities Computer Section at Cornell University in Ithaca, N.Y., agreed: “If by ‘manufacturer's graphics’ you mean a client GUI application used for the run-time operation of a BAS that must be installed and maintained on every potential workstation, as opposed to an application used for BAS setup, configuration, or commissioning, then the answer clearly is no. The software tools available to GUI designers for BAS, such as JavaScript and other scripting languages, supplement HTML (HyperText Markup Language) display technology to permit controls, such as buttons, scroll bars, sliders, and other user-input devices, to be displayed and actuated, thus, allowing operators to interact with the BAS through a Web browser with nearly the same look and feel of traditional client GUI.”

One should not be so quick to dismiss the value of manufacturers' graphics, the survey's manufacturer participant, Tom Zaban, P.Eng., vice president of sales and marketing for Reliable Controls Corp., said.

“Just because browser-based technology is ubiquitous does not mean that content (i.e., graphics) no longer is needed …, Zaban said. “The more people go online, the higher their expectation for quality information becomes.”

As the survey's controls-integrator participant, Brian Dutt, vice president of sales and marketing for Delta Controls Inc., explained: “Manufacturers often create higher-quality interfaces for use with their products. It is quite simple for a manufacturer to create additional properties and functionality within their controllers that go beyond those defined by open standards. This added functionality … is available to the end user only when utilizing the manufacturer's software interface.”

One could argue, Zaban said, that: “Theoretically, there are enough image assets on the Web to make any manufacturer's library redundant …, and maybe in time that could become true, but good luck. Try putting that into practice today. You would have to cope with the lack of images and the inconsistency in color, texture, camera angle, and resolution — all necessary to deliver a professional-looking end product. I would expect for the time you would spend piecing together a functional public-domain library you could hire a team of pimply faced kids to make a new library from scratch and do it cheaper with a better result. Then, you will need the animations. Forget it — game over.

“There is an intimate tie-in to each manufacturer's product and the behavior of any animation of modest complexity,” Zaban continued. “The frames of the animation are ‘coded’ to behave according to the bits set within the object, which, in turn, are based on values/states measured and/or calculated by the controller or derived by direct operator input. There is no consistent standard in the industry describing that relationship that I am aware of. … The nature of animations is just too creative to nail down to a standard that would cover a wide variety of cases.”

Summary. There seems to be agreement among the survey participants that the industry is moving toward browser-based graphics. Because such graphics require special objects and support features developed by direct-digital-control- (DDC-) system manufacturers, the creation of generic graphics is seen as expensive.

2. Is there a good reason not to consider using multiple vendors' products in a single system?

“There are several reasons to avoid mixing and matching, although the technical barriers essentially have been eliminated in recent years through the development and widespread adoption of standard networking protocols …,” advanced user Newman, who chaired the American Society of Heating, Refrigerating and Air-Conditioning Engineers' BACnet committee from 1987 to 2000, said. “The most significant impediment would be the need to become proficient with the configuration, programming, commissioning, operation, and maintenance of equipment from different manufacturers. This involves training, documentation, the need to have spare parts for each system, and so on.”

That does more than increase cost, controls integrator Dutt said.

“Developing intimate knowledge of a single manufacturer's product is spread across multiple individuals within a value-added reseller's (VAR's) technical team,” Dutt said. “If the VAR chooses to support multiple manufacturers, it typically will develop knowledge specialists for each product family. This increases the risk to the organization should the specialist choose to leave the organization. It also causes risk to the service and support of the project longer term.”

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