Article - November 2000
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Computer Graphic

John J. "Jack" Mc Gowan, CEM
Contributing Editor

"There have been a number of efforts aimed at creating standard bus-level protocols for automation systems. This only addresses part of the problem of creating truly interoperable systems. Our approach is to go one level higher and create a standard software framework that supports LON, BACnet and legacy systems in an open framework that is full Internet enabled" says John Petze, VP of Business Development at Tridium.

The term Automation may have different meanings depending on the application. Control automation in the building industry has come to mean execution of a series of digital sequences based upon a condition, a simple example being a space temperature control loop. The commonly accepted name for this process, Direct Digital Control, assumes that the control loop is executed by a microprocessor that resides at the piece of equipment. Yet the simple fact is that the same technology can be used to synthesize or integrate multiple different sequences for equipment that is currently seen as part of very different systems, such as SCADA (Supervisory Control and Data Acquisition). So what is control synthesis and why do we care? Another term for control synthesis is interoperability, and the key point in this article is that the opportunities for integrating control go far beyond the four corners of our familiar DDC box. This may be important for the owner because there are opportunities to eliminate disparate systems and redundant control networks, thus saving money and enhancing productivity. It may be important to the control contractor because it is possible that there are market opportunities for your expertise that you have not considered. It is highly likely that there will be a massive consolidation in controls related industries over the next decade, and the tools exist today to make this a win for everyone.

Control Applications

SCADA Equipment[an error occurred while processing this directive]To provide a context for this idea, consider three closely related industries that have been almost completely separate; Industrial Automation, Building Automation and Supervisory Control and Data Acquisition (SCADA) for Water facilities. Each of these industries has developed completely custom devices to fit their needs, but that is all starting to change. At a Water Industry Trade Show in June, US Filter, a major company in that business, unveiled a strategic alliance with Honeywell that is applying an Industrial Automation System to the Water Industry. This may be one of the first indications that consolidation is at hand. In the past custom devices have been applied in these, and many other industries, because there were specific needs that were not cost effective to develop for general application. For example SCADA systems required telemetry for communications. In a typical system there may be several hundred remote locations with very limited equipment, for example a water well with 400 horsepower electric motors, that require communication but may be far from phone lines. The control requirements are quite simple; time of day control, alarming and monitoring, but the communication requirements create a challenge

ASHRAE defines Direct Digital Control (DDC) as a closed loop operation (feedback and response) that is applied directly at the application. The key here is the word application, and as DDC has evolved, multiple applications have been addressed. The primary emphasis of ASHRAE's definition of course is temperature control, though the definition also encompasses other building related functions such as lighting control, fire, and life safety or building card access control. Many of the control sequences necessary to provide these functions are just as applicable for other applications, such as pump control for the water industry. The key is that with the advent of wireless technology it may be quite simple to migrate from telemetry to telecommunication, thus eliminating one of the major obstacles to using DDC instead of SCADA. It is important to note that custom reports may be necessary, but this may be easily accomplished with most DDC systems.


There are a number of interesting trends that may be observed in the control industry, and that could have far reaching implications for system design. First and foremost the number of different systems that we include in the Building Automation industry seems to continually increase. It is common to think of HVAC, lighting and load control under that heading, and of course fire and life safety also fit here. In the early 1980's during the first popularity surge for intelligent buildings, synthesis or integration of other systems that reside in buildings was also commonly discussed, such as telecommunication, vertical transport and even data communication for office automation. Today with the advent of communication standards and an explosion of new technology, synthesis of many more applications are possible. SCADA systems, as noted, need no longer be differentiated by the need for telemetry with the simple and cost effective access to wireless communication technology. The mobile commerce industry is offering a host of tools that allow for any type of microprocessor based device to use wireless communication via modem to a central site or via the Internet to a server and then on to the world.

Industrial Automation, of course, has always been the incubator for technology enhancements that later migrated to HVAC, for example the first DDC system was applied in the 1950's at an Oil Refinery in Port Arthur, Texas. Eventually this technology was adapted for buildings, but with the integration of data for enterprise wide management that is being driven by many facility managers, it is highly likely that some features like Web Browser interface may migrate from buildings to factories. Another interesting trend is the drive for standardized equipment that is application appropriate. In the past it may have made sense to use the same PLC for factory automation and HVAC control to standardize on control equipment. The first cost of this approach was high for HVAC control due to equipment cost and custom programming, but the savings in operations was seen as valuable. Today with network communication standards it is possible to apply the most cost effective control equipment in industrial applications and have one operator interface. This is viable for HVAC but also for many process loads that do not require high speed control loops or adaptive intelligence in sequences.

SCADA EquipmentInitially the observation is that technology obstacles, or requirements, like telemetry for SCADA, control loop processing speed for Industrial control and temperature operating ranges for exterior HVAC controllers may not be nearly as significant as they once were. Now take this dialog a step further and consider not only "control" systems but all of the systems in a facility. The systems already mentioned in this article fit in this list, but so do a host of others such as computerize maintenance management systems, utility bill monitoring systems and even business management systems! Companies like Tridium are offering some very exciting new options in this area. Tridium is helping to blur the line between these industries by offering products that allow owners to synthesize different systems, regardless of their native protocols, into a web-based system that hides the distinctions between different systems by "morphing" all of the data from the different systems into a standard Java object model. These objects then are used to present information to the user via a standard web browser. "There have been number of efforts aimed at creating standard bus-level protocols for automation systems. This only addresses part of the problem of creating truly interoperable systems. Our approach is to go one level higher and create a standard software framework that supports LON, BACnet and legacy systems in an open framework that is full Internet enabled" says John Petze, VP of Business Development at Tridium.

The drive towards enterprise wide control and common access to the data that resides in all of the many systems in a building will require systems that were traditionally "islands", to begin to at least share data. Consider for example the electric, natural gas or water meter. With Automated Meter Reading (AMR) Systems the meter is no longer an electro-mechanical device, but now a smart device capable of communication over a modem or a network. There has been a trend for two decades to move towards electronic meters, but AMR's today are capable of wide area networking, and there is a strong drive to standardize the communications for all these devices. Recently the industry has started to install Gateways with integral Web Servers that are not only used for the demand meter, but are being installed in residences and used by deregulated utility distribution companies to make power purchasing decisions.

Future possibilities

Perhaps some of the most exciting companies in the marketplace are those like Tridium and Silicon Energy who are achieving interoperability between a myriad of systems and providing high-level applications that add value not previously attainable. With solutions that they are offering, it is already possible today to implement real time control strategies based upon input from a host of sources beyond the space or outside air temperature. With both standard and customized equipment companies are now able to offer building control based upon anticipation of changes in market-based utility rate structures, or how your facility may be expected to respond to tomorrows estimated temperature based upon hourly weather data from NOAA (National Oceanographic and Atmospheric Association). Silicon Energys' EEM Suite™ can already provide this type of synthesized control. Control based upon real-time data that may come from anywhere in the World Wide Web is exciting, and means that the only limitation is creativity. If this type of control is possible now, how long will it be before; elevators, water treatment plants and industrial facilities are controlled by the same systems that automate our HVAC equipment?

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