SC Technology & Standards Content • Overview • Technology • Standards • Unsolved Problems Overview The purpose of this web page is to give an overview of technologies and standards that are judged to be of interest to the industry concerned with Building Automation, Control and Management (BACM). The overview also includes comments on the different technologies and standards that you may agree or disagree with – the intention is not to dictate an opinion, but to reflect the majority assessment of the sub-committee. Consequently it can be read as kind of a ‘state-of-the-art’ description, which will evolve over time, as it is questioned and improved, or when the industry has moved from its current position. Additionally we need a guideline for our work: • What are the goals for us to work together? • What will everybody gain from our communication in our BACS community? It is not enough to give a static state of the art description. This web page is partly a presentation of the established solutions – this should be the first part. But the second part should be a list of unsolved problems. This collection of open questions could serve as an open forum: • Between the members of our BACM group to exchange opinions, to cluster ideas and to find main directions for joint projects in the future. • To attract people from other communities to join our discussions, to share their ideas and (last but not least) to become members of our BACM TC in the future. Disclaimer The content of this page may not reflect the view of all individual members of the SC, but has been agreed to be published to create debate and discussion. Consequently your inputs – both on what was written and what was not (but should have been included) – are highly valued. Please direct them to any of the chairs of the SC: Brissman, Kabitzsch. Technology This section lists a number of technology areas that are of interest in the field of Building Automation, Control and Management. Each area includes a number of sub-technologies that are described, valued and commented – aiming to give a momentary view as well as a future perspective of the technology in question. Control The area of control may be divided in control theory and control strategies. Control theory appears to be a non-issue – manufacturers of control equipment for the most part use simple P, PI, or PID control loops. Although there were vendors proposing and delivering auto-tuning mechanisms, fuzzy logic control, and other innovative technologies, it appears that the processes in buildings, HVAC in particular, are relatively easy to control permitting unsophisticated solutions. Are there any signs of this possibly changing in the near future? A different movement in the control theory area investigates the influence of an underlying communications network in the loop. There have been several proposals on how to include stochastic delay modeling into the umbrella of control theory. The importance in this area is mainly driven by control applications which have stringent timing parameters. At first, this might not be relevant to building automation; at least for the classical set of processes being automated or controlled. In the future, more processes in the building may be subject to control, and may include applications with more critical timings. See also Soucek, S.; Sauter T.: Quality of Service Concerns in IP-based Control Systems. In IEEE Trans. Ind. Electron., vol. 51, no. 6, pp. 1249–1258, Dec. 2004. When it comes to control strategies traditionally they have been heavily influenced by the specifying consultants. An attempt to standardize the definitions of the functionality included in control strategies has been made in the EN ISO 16484-3 standard, see below. The new standard is expected to create more uniform specifications of the functionality of HVAC installations, making it easier to compare bids from different contractors. Communication Data communication is the very important glue that keeps a building automation system together and facilitates the added functionality compared with stand-alone systems. Our society in general has adopted more and more of communications technology during recent years, much of which is also directly usable in the building context. Internet Protocols -IP is believed to be among the most important technologies for our industry. IP networks are deployed on the Internet, in extranets, and in intranets. Several different media are involved – fiber, cables, wireless. IP is a powerful vehicle for enabling communication but it does not specify the content of messages in such detail that is needed e.g. to make two systems exchange a temperature value. IP serves as the intermediary network technology today. It is mostly found in building backbones and access networks to the field-area network. Technologies that provide mechanisms to be transported over IP include LonWorks (EIA-852), BACnet/IP and KNX/IP. The typical use cases for those protocols are (i) the connection of different field segments over routers, (ii) access to each field segment for management purposes, and (iii) protocol logging for troubleshooting. XML based methods many observers believe will play an important role in the future in doing that. Several XML initiatives may influence the area of BACM: • BACnet XML Working Group: BACnet/WS Web Services • oBIX – Open Building Information Exchange • OPC XML – OPC Foundation o OPC XML-DA (Data Access) – exists now o OPC UA (Unified Architecture), which is the next step to provide data access, trending and alarming by OPC with SOAP/XML None of these alternatives have come in use yet (except OPC XML-DA to some extent) and it is an open question what will happen. In addition to the three (proposed) standards, there exist a number of proprietary XMLbaase protocols, e.g. by Echelon or Tridium. These are being used in various applications, and hence the driving forces to create a standard for XML-based methods. It is not so much an open question, if this technology will get into use, but rather when. From our experience we are seeing growing interest in deploying XML-based interfaces. XML for end-to-end sensor-actor communication probably never will be a replacement for IP based intermediary network technology, except for those rare cases where Webbindding are the only solution. Traditional communications protocols evolved years ago and were adopted by our industry – examples that have survived are BACnet, LonWorks, Konnex (EIB), and Modbus. The use of these protocols is increasing, replacing proprietary solutions creating new opportunities to combine equipment from different manufacturers. Particularly in the area of field buses there is a strong strive to bring costs down. The solutions for the field level provided by the earlier mentioned protocols are all a compromise between costs and installation time. For example, a more robust and worryfrre alternative may have a higher cost associated to it. Wireless technologies may present a new solution to bringing the installed cost down. Over the past 10-20 years new RF solutions have developed into every-day use by many. Surely the time is soon here when a reliable, robust, easy-to-install and secure wireless network technology for connecting devices in buildings will have gained market acceptance and substantial shares of new and retrofit installations. The name of the technology has not been established yet, and there are several alternatives out there. However, with strong backing from many of the major players in our industry, the odds at the moment are in favor of ZigBee, the mesh networking technology based on IEEE 802.15.4, see below. RFID (Radio Frequency Identification) technology is used for inventory /asset management in different facility management applications, for access control (electronic locks) etc. Energy savings In the area of energy savings most of the focus in Europe today is on the Energy Performance of Buildings Directive (EPBD), see below. The demands that are put on the member states all are aiming at moving the member states in the direction of saving more energy. This European initiative may have followers in other parts of the world. Engineering Engineering of Building Automation, Control and Management systems is an area that has been more or less submitted to the manufacturers. Little interest has been paid from other parties in the industry – except when it comes to the end result of the engineering, i.e. the cost of a project contract for installing a complete system. Engineering is often as much as 25% of the overall cost of the contract, so it can easily be understood that better performance in this area in the end would benefit the customer – the building owner. What does engineering consist of? Here is a list of the most important parts: • Project management • Design, programming, test • Installation, commissioning • Training, documentation What can be improved from this list? The largest potential is believed to be in the areas of design tools (for implementing the contracted functionality) and Plug & Play features when installing or replacing equipment. HMI The area of Human Machine Interfaces (HMI) contains a number of different subtopics that are all important to provide the users of building automation systems with a user friendly and efficient way of interacting with the system. The following list is not complete but contains some of the more important ones: • Devices: PCs vs. touch panels vs. PDAs/mobile phones • Methods of providing graphics -symbols • User categories – different needs and skill levels • Ease of use – often claimed but seldom delivered Openness Openness is a buzz-word often used in our industry, but what kinds of openness should be included from a provider of a Building Automation System to be characterized as open? Here is a list of suggested requirements: • Standardized communication protocols • Standardized database • Standardized documentation • Standardized graphics • What else for the future? Standards This section lists a number of standards – existing and under development – that are relevant to Building Automation, Control and Management. Each standard is described and commented. EN ISO 16484 EN ISO 16484 – Building Automation and Control Systems – will include the following parts; 1. Overview and definitions -An overview and vocabulary to describe the objectives and interrelationships of all parts of the standard. 2. Hardware -Specification of the requirements for the hardware to perform the tasks within a BACS integration. It relates only to physical items or devices like operator stations, controllers, application specific controllers, field devices and engineering and commissioning tools. 3. Functions -Terms and requirements for specifications are listed to give guidelines to achieve consistency in documentation of specific systems. 4. Applications -Includes applications for general room automation and for sophisticated optimization of controls for heating, fan coil and induction units, CAV, VAV and radiant cooling etc. 5. Data communication protocol -Data communication services and protocols (BACnet) for computer equipment and controllers used for monitoring and control of HVAC and other systems of building services. 6. Data communication conformance testing -Technical requirements of the conformance test suite for data communication and the methods for testing the products for conformance with the BACnet protocol. 7. Project implementation -Methods for project implementation and integration of BACS. This standard defines terms to be used for project specifications and gives guidelines for project specific system integration. Project implementation can consist of two parts, the system implementation and, if required system integration. Parts 2, 3, 5, and 6 have been (or will be) published during 2005. Currently work is going on in CEN/TC247/WG3 to create part 7. A first draft of part 1 is also on its way. EPBD In Europe today there is much focus on the Energy Performance of Buildings Directive (EPBD). The directive calls for a number of different demands on the member states: 1. Develop methods for calculating the energy performance 2. Decide on minimum demands on energy performance for new buildings 3. Decide on minimum demands on energy performance for large buildings (>1000m2) that undertake large renovations 4. Develop energy certification of buildings 5. Perform regular check-ups of boilers and air conditioning systems and of the heating system in cases where it is older than 15 years To help with number 1, which is a necessary for 2, 3 and 4, rapid development of a series of standards has started with the goal to be finished during 2006. The standards cover many areas with the purpose to encourage the use of a common method to calculate the energy performance of a building. One part specifically has to do with the improved performance that can be expected when using different Building Automation, Control and Management functions. The directive formally should be implemented in January 2006, but there is a transition period of 3 years for some parts of it. This European initiative may have followers in other parts of the world. BACnet ASHRAE (American Society of Heating, Refrigeration and Air-Conditioning Engineers) began several years ago to define a vendor-independent communication protocol primarily for HVAC applications. They named it BACnet -a data communication protocol for Building Automation and Control Networks. The first release was in 1995, the now current version is from 2004. The standard is maintained and extended by a Standing Standard Project Committee, SSPC-135. BACnet is also a European and World-wide standard – EN ISO 16484-5. The standard includes several different media, making it suitable for use to connect different systems together on a high level, as well as connecting controllers and field equipment on lower levels. At the protocol level it is based on a client/server architecture. The application is modeled as a distributed set of server objects, whose properties can be accessed over the network. The popularity of BACnet is increasing, not least since the introduction of BACnet on IP networks (BACnet/IP), like a Local Area Network using Ethernet. Most vendors today offer a BACnet option to their systems, as a minimum BACnet/IP, but often also BACnet/MSTP, the RS-485 twisted pair option. In the early days BACnet systems were accused of not providing interoperability between vendors, but numerous ‘Plug Fests’ where manufacturers test their equipment with each other has made the situation today much better. BACnet is often referred to as the most open, vendor-independent alternative compared to other protocols. This is its major strength. It is also the dominant open protocol on the management level – connecting systems on the highest level. Its weakness is the field level where some other protocols provide more robust and easier to install alternatives. LonWorks Echelon Corporation of San Jose, California, created LonWorks in the early 90’s as a generic communications technology for ‘Local Operating Networks’ – or more frequently used – control networks. These networks may be deployed in buildings, homes, ships, machines, and many other application areas. Some of the characteristics of LonWorks are very robust physical layers, in particular for twisted pair and power line communication, and sophisticated upper layers providing very advanced features. The upper layers have made it possible to create standard profiles for different kinds of equipment – meaning that their communications capabilities are clearly defined and documented, providing a large degree of interoperability. These interoperability criteria are developed and maintained by the LonMark organization that provided conformance testing of devices to certify their capability to interoperate, plus promotion of the technology in general. LonWorks is an ANSI standard (ANSI/CEA/EIA 709.1-B-2002 and ANSI/CEA/EIA 852-A) for Home Electronic Systems and also a European standard (EN 14908) for building automation. With the CEA/EIA 852 standard, LonWorks can be extended over IP networks. IP-based backbones enjoy a growing installation base. Konnex Konnex or KNX is an open standard for home and building control that is based on the communication stack of EIB (European Installation Bus) but enlarged with the physical layers, configuration modes and application experience of BatiBUS and EHS (European Home System). It has sprung out of the electrical installation industry and has been widely adopted as an intelligent installation bus. The maintenance and development of the standard is done by the Konnex Association where most of the European installation equipment manufacturers are members. The KNX standard offers 3 different configuration modes for more or less experienced installers and larger or smaller projects, of which the E-mode (Easy mode) is particularly well known. KNX is available for twisted pair, TCP/IP networks, power line communication and Radio Frequency. KNX is a European Standard – EN 50090 for home and building electronic systems. DALI DALI (Digital Addressable Lighting Interface) is an IEC standard (IEC 60929) and finds its predominant use in building lighting control. It is plug-and-play to install, tailored to its application and integrated by luminaire manufacturers. It is designed to replace the traditional 0-10V interface. A DALI loop can manage up to 64 controllable electronic ballasts and up to 16 groups. DALI lighting controllers are available for different fieldbus connections, including LonWorks and BACnet. DALI controllers include features such as scene selection, dimming and fade time settings. Modbus The Modbus Protocol is a messaging structure developed by Modicon in 1979. It is used to establish master-slave/client-server communication between intelligent devices. Modbus is a de facto standard and truly open. Industry analysts have reported over 7 million nodes in North America and Europe alone. Modbus is considered very simple and straight-forward to implement and use and has been adopted not only by the industrial manufacturing environment but also be many manufacturers of equipment used in buildings. It has been implemented by hundreds of vendors on thousands of different devices to transfer digital/analog I/O and register data between control devices. Modbus has become very popular because it is free, very low cost to implement both in hardware (RS-232/RS-485) and software. It is however restricted to simple data exchange and is not used for more sophisticated needs. The maintenance and development of Modbus is done by Modbus-IDA. There have been several enhancements incorporated since 1979, including Modbus Messaging on TCP/IP. ZigBee Over the last 20 years radio technology has made tremendous progress: Lower power requirement, higher transmission data rates, and better reliability. After mobile telephones, wireless local area networks, and ad-hoc networking it now looks as time has come for mesh networks that are very suitable for more permanent installations in buildings. The major benefits are lower installation costs and better flexibility (easy to move). ZigBee is the name of a new RF networking technology that is based on top of the more basic IEEE 802.15.4 standard -Wireless Medium Access Control (MAC) and Physical Layer (PHY) Specifications for Low-Rate Wireless Personal Area Networks. The ZigBee standard adds the upper layers which includes the mesh networking features. Meshing is a term used to depict the capability for a specific message to be routed through other nodes dynamically, i.e. messages use different paths over time depending on how well the links function. This creates a very reliable network that can adapt to varying transmission conditions over time. The standard also includes application profiles for specific equipment of different kinds. So far (Dec 2005) only lighting control has been finalized but work is going on many other areas of technical equipment used in buildings. Unsolved Problems Advanced Control Typical borderlines of control theory are non-linear systems, delay systems and asynchronous sampled systems. For example, a different movement in the control theory area investigates the influence of an underlying communications network in the loop. There have been several proposals on how to include stochastic delay modeling into the umbrella of control theory. The importance in this area is mainly driven by control applications which have stringent timing parameters. At first, this might not be relevant to building automation; at least for the classical set of processes being automated or controlled. In the future, more processes in the building may be subject to control, and may include applications with more critical timings. Which methods are appropriate? See also Soucek, S.; Sauter T.: Quality of Service Concerns in IP-based Control Systems. In IEEE Trans. Ind. Electron., vol. 51, no. 6, pp. 1249–1258, Dec. 2004. Wireless Communication Which kind of tools (design, installation, commissioning, troubleshooting) exist for wireless field-bus nodes (ZigBee)? Which kind of tools do we need? Adaptive Energy Savings & HMI Energy saving is a trade-off between human comfort needs and energy costs that the user is willing to pay. To find the right balance, the BACM system must find out the individual opinion of everybody inside the building. This is a simple task for a clairvoyant, but how to do this job with BACM equipment? Automatic Engineering Plug & Play: What can be improved from the list of most important design steps: Design, programming, test, installation, commissioning, training, and documentation? The largest potential is believed to be in the areas of design tools (for implementing the contracted functionality) and Plug & Play features when installing or replacing equipment. But how to implement Plug & Play mechanisms for contracted functionality? Functional semantic: For (formal) specification of protocols, data frames or data types we have a lot of solutions. But what about the semantics of BACM functions, their meaning or dynamic features? How is a designer able to find out the right field device, software object or configuration from the (worldwide) market? In this context the EN ISO 16484-3 standard provides some guidance, but does it go far enough? Design intelligence: If complexity of BACM systems is increasing, traditional design strategies by human beings will be too expensive. Then we need more automatic design support from novel design strategies and tools. Are learning and adaptive design methods promising solutions in the future? -For early design steps in tools: Intelligent interpretation of the results of all former design decisions, hidden inside the data bases of the existing tool chain. The result would be a “self designing building”…? -During operation of the real building: Learning from behavior of weather, equipment, people etc. inside the building. The resulting building would have an internal “perceptive awareness”…? Tool interoperability: Most of existing tools have standalone usability. But in actual fact they are part of a long tool chain, going from one design step to the next. There is a need to interchange all these tools to transfer the former design results to the next tool (iterations must be allowed). By which methods we get such an interoperability of tools and design data bases? Improved Openness The SC should make a statement, what we consider as an "open" system. The target could be to take away the buzzword factor and define something for us. Is the usual term "making a technology under reasonable and non-discriminatory conditions available" enough for us to declare a system "open"? Do we have additional requirements that we want to amend to this definition?