September 2005 |
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A Guide to the Automation Body of Knowledge |
Vernon Trevathan |
Ken tries to describe our complete building automation industry in a brief chapter of ISA's Guide to comprehensive information about all major topics in the broad field of automation.
ISA - The Instrumentation, Systems, and Automation Society was founded in 1945, ISA is a leading, global, non profit organization that is setting the standard for automation by helping over 30,000 worldwide members and other professionals solve difficult problems. Based in Research Triangle Park, North Carolina, ISA develops standards; certifies industry professionals; provides education and training; publishes books and technical articles; and hosts the largest conference and exhibition for automation professionals in the Western Hemisphere.
A Guide to the Automation Body of Knowledge
provides you with comprehensive information about all major topics in the broad
field of automation. Edited by Vernon Trevathan with contributions from over
thirty leading experts from all aspects of automation, this book defines the
most important automation concepts and processes, while also describing the
technical skills professionals require to implement them in today’s industrial
environment. Whether you are an engineer, manager, control systems integrator,
student, or educator, you will turn to this book again and again as the ultimate
source on what is encompassed by automation.
http://www.isa.org/Template.cfm?Section=Books1&template=/Ecommerce/ProductDisplay.cfm&ProductID=7931
Ken - Thank your very much for your chapter contribution to the ISA Automation Book of Knowledge. The book is on schedule and looking like it will be a major contribution to the literature thanks to your help! Besides thanking you, I'm emailing to ask for your help in another important activity developing from the book. Your chapter, and others in the book, will also be a part of a Certified Automation Professional (CAP) Learning System that is now under development by our training group. Since the CAP Learning System will be a training tool, we need to identify learning objectives and test questions for each chapter.
[an error occurred while processing this directive] Here is a sneak preview of the chapter I prepared for this book.
Building Automation
Topic Contents
16.1 Introduction & Overview
16.2 History of the Evolution to Direct Digital Control (DDC)
16.2.1 Example of the Application of DDC
16.3. Open Protocols Use in Building Automation
16.4 How to Specify Building Automation Systems
16.4.1 CtrlSpecBuilder
16.5 Future of Web Services in Building Automation
16.6 Web-Based Facilities Operations Guide
16.7 Summary
16.8 Resources to Learn More
16.1 Introduction & Overview
This chapter is designed to provide insight into the industry which automates large buildings. Each large building has a custom-designed heating, ventilating and cooling (HVAC) air conditioning system to which automated controls are applied. Access control, security, fire, life safety, lighting control, and other building systems are also automated as part of the building automation system. These systems are viewed by building management on-site and off-site with standard computer technology. In the past, this was done by proprietary communication systems using telephone modems, but now the trend is to browser-based presentation using Internet access with open communication standards.
The names given to building automation systems are varied:
Plus others, based on building-based functions such as lighting control, fire/life safety, security, video, digital signage, etc.
Basic climate control systems (building HVAC) vary widely, depending on owner and building requirements and the mechanical engineer’s design. To provide insight into the complete process, this chapter includes an example of how the instrument design for a typical air handing system is laid out. The building zoning is determined by the design engineer and owner of the building and is based on cost versus comfort. Thermal zones usually reflect the internal thermal barriers of the building.
Most controls are based on simple feedback of space temperature. However, the complexity comes from optimizing the interaction of the central equipment—such as the chillers, boilers, pumps, and air-handling equipment—with the great number of individual zones that make up the HVAC system.
Solar control is sometimes used to operate window shades, but most North American building designs depend on brute strength to overcome heating and cooling requirements. The green building movement is slowly changing this type of thinking, encouraging passive designs and interactive control of the building envelope. Outdoor air is used when possible for free cooling, but many buildings have only minimum outside air to provide for ventilation. Temperature is generally sensed with low-cost thermisters.
The energy management control for a building can be as simple as time clock control or as complex as Gridwise, which provides connections based on interactive web information that allow the building to be a controllable load on the nation’s electrical grid. In smaller buildings and homes, the controls are often packaged and provided with the heating or cooling equipment.
16.2 History of the Evolution to Direct Digital Control or DDC
A brief history of control evolution provides insight to the development of direct digital control, or DDC, an industry foundation. The automated buildings evolution followed the growth of the pneumatic control industry for a century, seeing the gradual introduction of pneumatic transmission, followed by electric and electronic control. In the mid-1960s, electronic control evolved to multiplex control systems that evolved into the first computerized systems using head-end computers. This quickly gave way to mini computers, then ended with the personal computer and the DDC revolution. In the late 1970s and early 80s, the use of DDC exploded, greatly expanding the scope of the traditional building automation control market while displacing the traditional pneumatic control industry. The automated building control market growth curve went almost vertical. The decade between mid-1980 and mid-1990 saw the growth of many new control companies able to bring low cost, high functionality, proprietary protocol control systems rapidly to the market place. By the mid-1990s, the cost of DDC was much lower than the cost of pneumatics. This rapidly fueled the replacement of pneumatic controls and the expansion of traditional and non-traditional automation markets.
During the mid-1990s, the BACnet movement, “one of the first open communication protocols,” began to gain momentum, and a few systems were built around the evolving standard. About the same time, the industry started to follow the revolution that was occurring in other industries with products based on the Echelon chip. Standard protocols became something the industry wanted to achieve. Slowly, but surely, the number of proprietary communication standards were reduced and replaced by open-standard communication protocols.
The next revolution to hit was the Internet/intranet and browser-based presentations of everything. This forced all companies to look hard at what the information technology (IT) industry was doing to standardize presentation models. Some companies had built their new systems around IT thinking and were able to rapidly follow, and even lead, this new trend. Once DDC concepts were embedded in browser-based presentations, their convergence fueled rapid evolution with wireless cell phones, personal digital assistant (PDA) interfaces, e-mailed alarms etc. With this followed the rapid evolution that further explored Internet capabilities and increased the understanding of the complete power of the newly inherited tools from the Web environment; with this, building automation functionality exploded. Figure 16-1 provides a visual portrayal of all these events.
Figure 16-1: Automated Buildings Evolution
16.2.1 Example of the Application of DDC
An example of the points list for a basic DDC for an air handling system is laid out in Table 16-1, shown on the following page. Once you conceptually understand how this is done, you will see how automation is applied to other building components. Sensing and control points are provided for each air system, plus all other major pieces of equipment provided in the mechanical building design. Both hardware and software points are specified.
Table 16-1: Example Points List for a Basic DDC Air Handling System
The points list provides each hardware and software point with a unique number, shown on Figure 16-2 on the next page. The point type is indexed in a specification which provides a complete detailed specification for each end sensing and control device as well as all software points.
Figure 16-2: Unique Number Provided for Each Hardware and Software Point
The graphic is followed by the control language which shows the exact relationship between the real and virtual points in the automation system presented in a basic IF, Then, Else, control language.
This is an example of one air system. In an extremely large building, there could be hundreds of air systems, typically one per floor in high-rises, plus thousands of individual terminal zones—each with their own DDC control. In addition, central equipment such as chillers and boilers to provide heating or cooling all have their own control systems. These DDC control points are all networked together to allow interaction of all points. This is done in the control language and the presentation to operator is via a browser-based interface.
16.3 Open Protocols used in Building Automation
In the past, proprietary protocols were used to network DDC points. However, today it is more likely open protocols such as BACnet, LonWorks and/or TCP/IP, oBIX , and Niagara standards would be used.
BACnet is an acronym for a data communication protocol for Building Automation and Control Networks. The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) maintains a BACnet website. See: http://www.bacnet.org/
LonMark International is a global membership organization created to promote and advance the business of efficient and effective integration of open, multi-vendor control systems utilizing ANSI/EIA/CEA 709.1 and related standards. See: http://www.lonmark.org/
TCP/IP is the acronym for Transmission Control Protocol/Internet Protocol, the suite of communications protocols used to connect hosts on the Internet.
oBIX stands for Open Building Information Xchange, 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. See: http://www.obix.org/
Niagara is a different way to address the challenge of creating true interoperable and open systems. Niagara takes data from diverse systems and "morphs" all of the data into uniform software "components." It's a comprehensive software framework designed to address the challenges of integrating diverse smart devices into unified systems. These components can then easily be assembled into applications—for example, dynamic displays, control sequences (even across different systems and devices), alarms, schedules, reports, etc. Niagara makes it possible to expose all this data to the enterprise in a unified IT-friendly way. Niagara combines the capabilities of network management, protocol conversion, distributed control, and the user interface into a single software solution that can operate on a wide range of hardware platforms from very small to the very large. It can be used on PCs, on servers and in small, embedded controllers. See: http://www.tridium.com/
The art of the automated buildings industry is connecting and creating the correct relationships of these thousands of DDC points, while providing communication to a Web browser with open protocols. Rapid evolution in the automated buildings industry has been fuelled with the standardization of communication protocols.
Figure 16-3 has been copied from the Reliable Controls Web site, with permission (http://www.reliablecontrols.com/). It provides a good example of how of an open protocol operating system using BACnet protocol takes the DDC points and creates a relationship for each point in a control language (BASIC Code) and displays them on a standard internet browser.
Figure 16-3: Display Showing How BACnet Protocol Works
16.4 How to Specify Building Automation Systems
What
is CtrlSpecBuilder?
CtrlSpecBuilder™
is a free online productivity tool
for preparing bid specifications for HVAC control systems. CtrlSpecBuilder can
prepare BACnet specifications or specs that allow other protocols. You can view
the spec online and download it as a Microsoft Word file.
CtrlSpecBuilder provides tool for preparing quicker, easier specifications
A new website has been launched providing HVAC engineers with a new productivity tool. Previously, engineers wrote specifications from scratch, cut and pasted from previous projects, or relied on proprietary vendor "canned" specifications. CtrlSpecBuilder is a free, on-line tool that prepares non-proprietary, custom specifications. It follows ASHRAE Guideline 13-2000, specifying DDC systems, and CSI MasterFormat for section 15900. This tool also generates point lists and sequences of control for all HVAC equipment in the project, and can provide specifications in U.S. or metric units.
CtrlSpecBuilder can be accessed at www.ctrlspecbuilder.com.
16.5 Future of Web Services in Building Automation
The following is an excerpt from an article published January 2002 on AutomatedBuildings.com’s web site. The article, titled Information Model: The Key to Integration (http://www.automatedbuildings.com/news/jan02/art/alc/alc.htm), has been widely read and is a cornerstone for web-based evolution. Its authors are Eric Craton, head of product development. and Dave Robin, head of software development, at Automated Logic Corp., Atlanta, Ga.
Let's look at the four trends in terms of Web services:
1. 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 work orders, energy consumption and forecasts, as well as traditional building automation information.
2. Bandwidth is getting cheaper - A Web service can now deliver types of content (streaming video or audio, for example) unthinkable a few years ago. As bandwidth continues to grow, Web services must adapt to new content types.
3. 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.
4. 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.
16.6 Web Based Facilities Operations Guide
In
August of 2002, I prepared a supplement for Engineered Systems Magazine,
called A Guide to Web-Based Facilities Operations
http://www.automatedbuildings.com/news/aug02/articles/ksin/ksin.htm. Here’s
an except:
By Ken Sinclair, AutomatedBuildings.com
Doing more with less by using Web-based anywhere information to amplify your existing building operational resources.
The reality of today and tomorrow's economy is that we will be doing more with less to effectively manage our buildings. Our saviour is that technology in the form of Web-based everything is now providing us a path to improved communications, while simplifying the movement of complex building information to the evolving Building Operations Specialist.
The rapid movement of the building automation industry towards Web-based allows us to interweave critical dynamic building information into a browser-based anywhere presentation. This allows us to concentrate and amplify our existing building operation resources and operators into virtual operational centres, in which all critical information is exposed to all stakeholders.
This visible-from-anywhere information allows authorized users to provide the correct input, management and dollar accountability skills that will provide excellent comfort/energy performance with total accountability.
Web-based presentation of dynamic building information allows not only operators to operate from anywhere with full functionality, it allows interaction of contractors, equipment suppliers, and consultants to provide valuable feedback and feed-forward information to the building operating equation. Upper management can also participate by having browser-based bottom line screens that provide the dynamic proof of the success or failure of building performance.
This new concentration and amplification of existing building operational resources and personnel will provide a strong re-focus on the values of good operating principles.
This focus will cause management and operations to re-establish communications on what is important and what is required to achieve cost effective excellent building operations.
16.7 Summary
We are witnessing a large building automation industry converging with corporate enterprises. As technologies converge, clients' expectations are fueled by the ease of access and freedom of information on the Internet. The scope has increased to encompass environmental control, energy metering/accounting systems, lighting control, life safety/fire, security, communications, high tech tools, Web resources, and interactive information systems. With the trend towards IT-type solutions, video, card readers, and enterprise-based solutions are all becoming an active part of what is now called building automation.
16.8 Resources to Learn More
Below are some of the resources available free with the online magazine, AutomatedBuildings.com (http://www.automatedbuildings.com), that will help you learn more about the industry. The magazine is updated monthly and provides connection to almost all the dot coms in the evolving automated buildings industry. If you have any questions, please e-mail me at sinclair@automatedbuildings.com
Automated Building Systems Education
http://www.automatedbuildings.com/frame_education.htm
The rapid changing Automated Building industry has always required that all players be constantly re-educating themselves to keep current, but never has there been a time when this is so important.
Technology Roadmap for Intelligent Buildings http://www.automatedbuildings.com/news/jan03/review/roadmap.htm
This 60-page glossy roadmap also available in a (66 pages) Adobe Acrobat PDF, 2.3 MB file is an excellent starting point for our large building automation industry to begin its reinvention and repackaging and to get on with the task of helping create an even better roadmap.
Intelligent
Building Ranking System
This Task Force is developing an
online tool intended to assist building owners/managers, the commercial real
estate industry, and other industry stakeholders to assess the level of
integrated systems within a building (a Building Intelligence Quotient - BIQ). A
comprehensive list of intelligent building criteria has been developed as well
as a "ranking matrix." The next phase of this project is to develop content
detail on each line item in the matrix to be available as part of the online
tool for ease of use by all industry stakeholders.
Middleware White
Paper
The paper defines middleware and describes a number of
case studies where middleware has provided a solution to integrate new
intelligent building technology implementations with legacy systems.
Building Control
Network Protocols White Paper
Communications protocols are simply a means by which different systems may
communicate. They are the message formats and procedures used to transfer
information, in an understandable form, from one device, or array of devices, to
another. They permit products from different vendors to communicate with each
other and interact to produce intelligent integrated building systems and manage
and interface with these products as if the same vendor supplied them all. This
paper, prepared by the Continental Automated Building Association (CABA)
Intelligent & Integrated Buildings Council Building Protocol Task Group explores
four of the most common protocols used today and compares a number of the
parameters that “assist the large building industry to understand the strengths
and overall features of the building control communication protocols that are
available for use in designing and implementing an “Intelligent Building.” CABA
Resources can be found at:
http://www.caba.org/councils/council-pubs.html
Best-Practices Guide for Evaluating IBT
This guide, authored by Kenneth P. Wacks, Ph.D., builds upon the Technology
Roadmap for Intelligent Building Technology. This paper consists of criteria by
which intelligent building technologies can be evaluated. The topics in this
guide are important for various audiences, such as building owners and managers,
intelligent building designers, and installers.
The Builconn Story
http://www.automatedbuildings.com/news/mar03/articles/builconn/bcon.htm
BuilConn intends to help integrators deliver a pragmatic approach to integration, not product or technology based, but solutions oriented.
Bring the Power of the Internet
http://www.automatedbuildings.com/news/jul00/articles/tridium/trid.htm
Perhaps no other technology has had the profound impact on virtually everything we do than the Internet. It is changing the way we make purchases, the way transactions are conducted between businesses, the way in which we obtain information, and the way we communicate with one another. The above article discusses how the power of the Internet is being adapted to real-time control and automation systems.