Integrated management and control of building services

Clima 2007 Wellbeing Indoors Key-note lectures Integrated management and control of building services Dipl.-Ing. Hans R. Kranz VDI HAK Consulting (Building Automation), Germany for Siemens Building Technologies, HQ Switzerland Hans@Kranz.com SUMMARY Professional building owners and facility managers require system solutions featuring integrated building management comprising building automation and control along with fire safety and/or security for the operator and at technical levels. Those solutions require coordinated procedures during the design phase as well as during the execution phase. The integration of different systems is carried out by using standardized communication protocols. One of these protocols to combine different building systems is the globally accepted protocol according to EN ISO 16484-5. The same standard, Part 3 defines the BACS functions. The definitions are valid for the entire branch of the building automation and control (BAC) industry to serve as a common language for all those involved in the design, implementation and operation of such systems. A functional networking of systems from different disciplines calls for involving complex efforts in terms of design engineering and implementation. The uniform object model of provides the brand and system neutral application and WEB services for interoperable integration with enterprise systems and other BACS using XML and the internet technology for networking, the transport of data. The standards for communication protocols in the various fields of building applications are, LonWorks with LonMark and KNX/EIB as well as more or less open methods as OPC, and MODbus. LonWorks is a national American and national European standard under the property rights from Echelon Inc. used mainly for data transportation and complex functionality in the field of room automation and smaller BACS. LonMark is a private standard to achieve interoperability using LonWorks products. KNX/EIB is also an American and European standard, but for 100% interoperability of products used in general electrical installation that also includes integrated room automation. The field of building automation and control and the integration of related building services needed a more comprehensive functionality. So became the international communication standard for BACS. Both, LonTalk (the transport protocol of LonWorks) and KNX/EIB have become a normative part of and therefore they are already part of the global EN and ISO standard for building automation and control systems. To use LonMark products within a environment, a Gateway to match the different semantics is necessary. already has defined provisions for the functional integration of integer fire safety and access control systems supporting the standard; the life safety communication objects and services. 29

Clima 2007 WellBeing Indoors Abstract Book The question of responsibility in projects with combination of autonomous systems for safety/security alarming and building automation and control is a serious matter of the various construction contracts and is not covered by standards yet. INTRODUCTION Integrated technical building management Technical building management probably represents the most important task within the scope of facility management while a building is being used. This is where all technical tasks to manage a building and its equipment come together. The control of plants for technical building services as well as with building operation monitoring for life safety and security management, energy management and supervisory control for of power distribution installations are the tasks for technical building management. The operating of modern industrial and commercial buildings requires clearly delineated building management tasks: Commercial building management focuses on managing and controlling processes. Infrastructural building management for general services rendered during building use. Technical Building Management with tools for operation and supervision. Communications for human interaction and for alarm notifications is using facilities such as telephone, pager, intercom, radio, and staff paging systems. However communication within and between technical plants is carried out via networks using communication protocols. Com m er cial BM Infrastructural BM Technical BM Safety & Security Building Automation & Control Management Safety Security alarm organization Automation BACS supervision and operation Safety alarming Security interlocks General monitoring BACS interlocks BACS HVAC controllers Figure 1. Technical building management and different systems in interaction. The discussion of system integration has become an increasingly important topic on the agenda of engineers and other experts involved building automation and control systems 30

Clima 2007 Wellbeing Indoors Key-note lectures technology. This discussion is influenced by contributions from the different bus systems or networks available for building applications. The heart of the matter is to solve the problem of exchanging unambiguous functional information between different technical systems. Comprehensive, project and estate-specific data management with a building management system will be cheaper from the lifetime point of view because the owner only has one database that needs to be managed and updated. It also eliminates data inconsistencies resulting from a multitude of different local or department-specific databases. The user can then transform the financial advantages into increased competitiveness. RESULTS Combined technical building systems To understand the needs of systems integration, first a definition the different systems installed in a building is essential. The possibilities of an interoperable connection between life safety/security alarm systems and systems for building automation have to be considered. Figure 2. The different disciplines to be interoperable combined. The operating of modern industrial and commercial buildings requires clearly delineated building management tasks. The European standardization bodies have subdivided the management tasks as follows: Commercial building management Commercial building management focuses on managing and controlling processes. Examples for commercial building management are: Contract management, 31

Clima 2007 WellBeing Indoors Abstract Book Tennant billing, Cost planning and controlling, Object accounting, Procurement, Project management. Infrastructural building management The infrastructural building management comprises general services rendered during building use such as: Security services, Guard services, Telephone services, Cleaning and waste disposal, Moving services, Campus services, Winter/snow removal services, Courier services/internal mail services. Life safety and security systems We can subdivide these systems into: Danger Alarm Systems: Fire alarm systems (fire safety), Burglar alarm systems (security), Raid alarm systems, Transmission systems for such alarms. Often the following installations are combined with the detection and alarming systems: fire extinguishing devices, fire alarm devices, CCTV systems for room monitoring, access control systems, watchman's reporting systems. Criteria for life safety and security systems From the security engineer s point of view, the terms "integrity" and "integration", on closer consideration, become antonyms. The term "integrity" is an important factor within their security concept. A look in the dictionary might be helpful in casting light into the depths of terminological confusion. integer (Latin adj.): untouched, entire, soundness; integration: the act of combining or adding parts to make a unified whole. Asking the users of security systems about their expectations with regard to the performance and usefulness of these systems, their main criteria are as follows: fail-safety/availability, low incidence of false alarms, fastness and reliability of repair service, state-of-the-art technology, 32

Clima 2007 Wellbeing Indoors Key-note lectures user-friendliness, service quality, delivery safety, confidentiality. (It is interesting to note that the above criteria frequently even range before the price!) Building automation and control systems (BACS) The concepts of supervisory control systems, "centralized control systems" or "building services management systems", have been supplanted by the term "building automation and control systems" (BACS), as a complete system for digital measuring, control, supervision and management. Almost invisibly, building automation and control systems and their operators ensure ecological, economical and safe operation of a building. The past experience made sure that it never would work sufficient to interconnect functions without standardized semantics. Functions within the building automation and control systems The BACS industry has learned that automatic functions need to become clearly defined and to be standardized for reducing the risk during tendering and construction (for both sides). This includes the I/O-functions as well as the complex processing and optimization functions such as "start-up control", "sequence control", "frost protection", "night cooling mode", "peak load limitation", "long term history", "dynamic display" etc. Therefore the industry hardly is promoting standard descriptions of building automation functions and of a communication standard describing semantic communication objects. The common definition of BACS functions is given in the global standard EN ISO 16484-3 to serve as a common language for all those involved in BACS projects. Fifty standardized functions include the I/O-functions as well as the complex processing, optimization and operator functions. Those fifty standardized functions cover: 1. Hardware-related and communicative (shared) input and output functions for event detection, measuring, counting, switching and actuating the "basic I/O functions, 2. Functions for monitoring and display of the different processes, as well as alarm functions in case of faults or of limit violations, 3. Processing functions for safe local automation - closed-loop and open-loop and PIDcontrol - of building services and user-specific installations, 4. Processing functions for energy-saving operation of the different processes (local optimization), 5. "Centralized" processing functions for time scheduling and comprehensive optimization strategies covering all areas and components of a building (general optimization and coordination of plant operation), 6. Process control functions for "human system interface", including service operation on the "field level" with local direct process control and indication devices, 7. Management functions for analysis and statistical display of current or historical process values to facilitate decisions, 33

Clima 2007 WellBeing Indoors Abstract Book 8. Tools for calculation or estimation of optimized operation parameters, and for combination and programming of new modes of operation, 9. Functions for data exchange and interoperability with other systems (system integration), 10. Remote control or telecontrol functions via the web or public networks, 11. Tools for modifications, expansions, and testing, 12. Data archiving functions for backup and restore. The complexity of combining systems Fire detection systems have been integrated with door locks and with HVAC fan and damper controls for smoke management for several years, but these systems have relied on relays controlled by the fire alarm system to override the normal controls. This kind of integration has primarily involved constant-volume HVAC systems and required only on/off control of fans and dampers to be moved to fully open or fully closed positions. Many modern HVAC systems are far more complex. Variable air volume and individual room control systems are used to reduce energy consumption. These systems require sophisticated control algorithms to operate either a continuously variable-speed fan or inlet guide vanes to control the static pressure in the supply air duct. Variable air volume boxes control the airflow from the supply duct into individual rooms by modulating dampers. What is needed is a way for the fire alarm system to command the HVAC control system to enter zone wise a smoke control mode and let the HVAC controllers manage the equipment. Purchasing of system integration To purchase (and to offer) system solutions featuring integrated building management - fire safety and/or security along with building automation and control - coordinated procedures during the tendering phase, the construction phase as well as during service are required. Another important aspect is the intentional interdependence of different functions. This means that, for instance, signals from safety and security installations (fire/burglar alarm) should trigger suitable reactions in the lighting, elevator and supply systems. Mutual exchange of electronic information between the different systems, without restricting their individual autonomy, would thus be useful for all systems involved. Damage to staff and/or buildings can be limited through automatic "secondary" actions in the technical installations initiated by alarms from the safety and security installations, which, in turn, initiate "primary" actions (emergency call, fire extinction etc.). In many cases, these functional chains are stipulated by the laws on the erection of buildings. Integration is not just a question of supplying equipment, but it is a task in its own right. For this reason, the networking of functions requires that the objects, properties and services used for the interaction of these functions are standardized as well as there is a need to restrict the methods for the data transport (the lower communication protocols in the ISO/OSI reference model), i.e. the interface definitions must describe the data transfer medium, the transport protocol, but above all the "application objects". 34

Clima 2007 Wellbeing Indoors Key-note lectures Common functionality due to common standards Alarm procssing Time schedules Trending History evaluation Functional peer-to-peer communication HVAC HVAC Life Safety Life Safety Accesscontrol Accesscontrol Services or third party systems for example Costs of integration Figure 3. The van diagram of system integration and standardization Characterization of combined and integrated systems Combined systems fulfill their functions with jointly used system components within the valid standards, making sure that there is no impact of faults on the defined main functions. If faults occur in a specific installation these have no impact on any other system. Integrated systems are characterized by a joint utilization of system components with possible interferences between system components. In this context, new and more detailed regulations and standards are necessary which take into account the need to preserve the integrity of the individual system components. The discussion of system integration has become an increasingly important topic on the agenda of engineers and other experts involved in alarm systems technology. This discussion is influenced by contributions from the different bus systems or networks available for building applications. The heart of the matter is to solve the problem of exchanging unambiguous functional information between different technical systems. All together is what we call systems integration. Methods for combining different systems Coupling of different systems can be implemented through direct "parallel" transfer of each information via coupling relays, or by means of "serial communication" in the case of larger building complexes. The different systems must be able to "understand", but not interfere, with each other. It is even more important that the aforementioned actions/measures do not reduce the functionality of the involved systems or installations. Of course, it also is necessary that the performance of different integrated systems can be accounted for individually (acceptance test/warranty). Furthermore, we have to be aware that systems integration or simple coupling of systems is subject to certain restrictions caused by safety and insurance regulations. We have seen that the principal expectations of the two user groups for automation and safety differ considerably. Nevertheless, it is important to look for common ground because there is 35

Clima 2007 WellBeing Indoors Abstract Book undoubtedly a large demand for combined/integrated systems on the market. However, it is important to judge these systems on the basis of safety aspects. Great diversity and complexity also mean an increased interdependence between the different systems. The different processes required for project planning and design, erection, commissioning, acceptance test, operation and service involves a continually increasing number of people who have to cooperate and communicate by means of various different interfaces. Is OPC a solution? Control devices and operator interfaces often are interconnected via an OPC interface. OPC is a general industry standard depending on and restricted to the procedures of the former Microsoft Windows operating system, it does not work under MS Vista. It also is not a standard in the ISO/EN sense. It is used for the connection of PLC s (controllers) and monitoring stations under Windows. For professional BACS, OPC has too many functional restrictions and limited reliability with respect to the data transmission within Windows-PC. OPC does not use semantics, data points and application objects. This means that the relationships between the functions of an object, e.g. between a counter input and the associated limit values and other parameters get lost. It requires double and more engineering efforts because all variables of a control data point need to be created within the controllers and to be re-created for the monitoring system. Uniform Object Model One can easily imagine that a well-planned data model for building automation and control is a lucrative asset both for owners, for prime contractors and for facility managers particularly if this data model is based on a globally accepted International Standard. A uniform data model, however, is only possible through the creation of a uniform object model which enables access to the internal data of different systems. Common ground Fortunately, with we have the global standard that provides such an object model, the required procedures and data access services. And it supports the appropriate data transport methods by referencing the most common networks used in buildings. In the following we will have a closer look to. What is? is originally the ASHRAE data communication protocol for building automation and control networks. The field of application covers the communication needs systems for applications such as heating, ventilating, and air-conditioning control, lighting control, access control, and fire detection systems, and some more are in development [1]. was not intended for use in the application fields for home automation, medical applications, white and brown goods, and consumer electronics. 36

Clima 2007 Wellbeing Indoors Key-note lectures After a parallel voting within ISO and CEN, became an ISO and an European Standard in 2003. It now is: EN ISO 16484 Part 5 BACS protocol [2] [3]. EN shows that this also is a National Standard in 30 European (CEN) countries. The protocol is describing: 1. Object types for application messages, 2. Services for data-/information access, with messages and their format and syntax, 3. Data transport to convey data by referencing standards. with networking options (LANs, WANs, Dial-up), 4. Joining networks together to form "internetworks". is designed specifically for building operation - some functional examples are: Alarm and event processing, scheduling, trending, command prioritization, control logic, life safety and security/access objects. But: The protocol does not specify the system itself, only provisions for interoperability of different systems or products. Object Types The objects represent the behavior of physical inputs, outputs and software processes. Each object is characterized by a set of properties that govern its operation. The Standard in the moment defines a collection of 28 standard object types. For example, an analog input is represented by a Analog Input object that has a set of properties that include its present value, sensor type, location, alarm limits, and others. Some properties are required and others are optional, depending on the functional use. A device is represented by an appropriate collection of network-visible objects. Once the information and functionality of a device are represented on the network in terms of standard objects and properties, messages can be defined to access and manipulate this information in a standard way. Control Device must object Device depending on process and user objects Analog Input Binary Input Analog Output Binary Output Analog Value Binary Value plant operation objects Command Alarm, event objects Notification Class Event Enrollment Multi-State Multi-state Input Output Averaging Group life safety objects Life Safety Life Safety Point Zone Multi-state Value Loop management objects File Schedule Calendar User objects Trend Log Program Figure 4. a) The recent object types, and b) objects in a device The object-oriented structure also provides a way to add new application functionality to by defining new objects and/or new application services. The safety/security additions were developed with assistance from the fire alarm industry and have been approved by the committee. Other new object types have been developed for video surveillance (CCTV), access control, other security applications, utility and lighting control integration. Hey are being integrated into the global standard soon. 37

Clima 2007 WellBeing Indoors Abstract Book Application services A communication with is described by reading and writing of information as contents of the objects properties. The definitions are unambiguous and complete. 1. Alarm and Event Services, 2. Data reading and writing Services, 3. File Access Services, 4. Object Access Services, 5. Remote Device and Network Management Services, 6. Virtual Terminal Services (for engineering), 7. WEB services for integration with enterprise systems using XML. XML is a mechanism to describe information in a manner that is flexible and can easily be communicated across IP networks. Web Services can best be described as a mechanism for applications (both system and device-centric) to communicate with each other across the Internet and intranets. These services include provisions for Scheduling, calendar and time depending actions and for Trending with Logs of analog values and events. s data exchange philosophy follows the well known client and server concept, but dedicated to functionality not to certain devices. Additional is providing procedures for applications and other services. Examples are the prioritizing of event notifications and commands. Other procedures exist for system start up, power recovery, and failures with additional error, reject, and abort codes. Networking Options provides a wide variety of options for the transport of data. These options comprise: 1. Ethernet, IEC 8802-3, 2. ARCNET, ATA/ANSI 878.1 3. Master-Slave/Token-Passing (MS/TP), ISO 16484-5, EIA RS 485, 4. Point-to-Point (PTP), EIA RS 232-C 5. Echelon's LonTalk, EIA/CEA 709.1-B 6. /IP, (Internet protocol), 7. /WS (Web services), ISO 16484-5 Am. 2004-c 8. In recent discussion are wireless networks such as ZigBee or Bluetooth, WLAN already is provided by Ethernet/IP. The first option is ISO 8802-3, better known as Ethernet, also together with the Internet Protocol (IP). It is the fastest option and is typically used to connect workstations, controllers and high-end field devices. Further on, in combination with the internet protocol Ethernet develops as the most future proof method. The second option is ARCNET, which comes in slower, lower-cost versions (mainly in US). defines the MS/TP (master-slave/tokenpassing) network designed to run over twisted-pair wiring. Echelon s LonTalk network can also be used. The Ethernet/IP, ARCNET, and LonTalk options all support a variety of physical media. also defines a dial-up or point-to-point protocol called PTP for use over phone lines or hardwired EIA-232 connections. 38

Clima 2007 Wellbeing Indoors Key-note lectures A key point is that messages are the same no matter which LAN is used. This makes it possible to easily combine LAN technologies into a single system. /WS Web Services facilitate integration of BACS and "enterprise" systems for scheduling, energy management, preventive maintenance, and other global applications, using XML, SOAP and other standard Internet Protocol capabilities. "Native" LAN - Ethernet, ARCNET, MS/TP, LonTalk, or /IP Workstation Field Panels Vendor A Vendor A Vendor C Sensors and Actuators Native devices provide communications directly, device to device Figure 5. A flat architecture LAN - Ethernet Net 1 Workstation Vendor A Field Panel Ethernet to ARCNET Router Routers - Sensors and Actuators Ethernet to MS/TP Router LAN - ARCNET Net 2 LAN - MS/TP Net 3 Field Panels Field Panels Vendor C Vendor C Sensors and Actuators Sensors and Actuators "re-package" messages and re-transmit them unchanged Figure 6. A hierarchical architecture allows both 39

Clima 2007 WellBeing Indoors Abstract Book LAN - Ethernet, ARCNET, MS/TP, or LonTalk Gateways - Workstation Vendor A Field Panels Vendor A Sensors and Actuators Proprietary LAN to Gateway Non- Field Panels Sensors and Actuators must "translate" messages before retransmission Figure 7. Integration of existing systems by gateway Workstation Web / XML Data Client /IP HTTP or XML/SOAP Internet /WS /IP HTTP or XML/SOAP /IP Web / XML Data Server /IP over Ethernet Vend or A HVAC Vend or A HVAC Vend or A HVAC FIRE Vendor A LIGHTING Vendor A SECURITY Vendor A Figure 8. via internet maintenance is maintained under ASHRAE continuous maintenance procedures by a committee (SSPC 135) representing all sectors of the industry, including liaisons from Europe and Asia. The current ASHRAE SSPC 135 Working Groups: 40

Clima 2007 Wellbeing Indoors Key-note lectures 1. Applications (AP-WG) 2. Internet Protocol Issues (IP-WG) 3. Lighting Applications (LA-WG) 4. Life Safety and Security (LSS-WG) 5. MS/TP LAN Issues (MS/TP-WG) 6. Network Security (NS-WG) 7. Objects and Services (OS-WG) 8. Utility Integration (UI-WG) 9. XML (XML-WG) Changes can be proposed at any time by the public or a committee member. All changes are subject to public review and comment. There are formal liaisons with: - ABOK (Russian HVAC society), - CEN/TC247 (Building Automation and Building Management), - IEIEJ (Institute of Electrical Installation Engineers of Japan), - NEMA (National Electrical Manufacturers Association), - SIA (Security Industries Association), - SWEDVAC (Swedish HVAC society). and Conformity Open communication is designed to enable the erection of dissimilar systems with common functionality, including systems with products and/or engineering by different suppliers and manufacturers. During the development of interfaces and other software, faults with the implementation of communication protocols cannot always be avoided. It therefore is necessary to test the devices for conformity with the given specification or standard. The global standard already has such a test specification as EN ISO 16484-6. The association International has created the Testing Laboratories (see BTL-sign) in USA, Europe and India. This testing is a type test of whether or not the reaction of the product s software being tested conforms to significant test parameters of the protocol. These tests are carried out by authorized institutes, in accordance with standard testing conditions, so as to ensure that all products are tested under identical conditions. These tests do not provide insights into the dynamic behavior of the test object within an integrated system as a whole. Figure 7. The test logo Only an interoperability test under typical working conditions which includes all the different products involved in one project would bring up the system behavior under different fault conditions. But this can be very expensive indeed so it is better to leave this task to a trustworthy company. 41

Clima 2007 WellBeing Indoors Abstract Book testing The Companion standard ANSI/ASHRAE 135.1, Method of Testing Conformance to was published in 2003 [4]. The functionality of listed products is published on a web site, accessible to everyone: www.bacnetassociation.org. Testing requirements and procedures are made public. Most testing tools are easy to obtain from http://sourceforge.net/projects/vts. Another automated test software was developed in Europe. Information is given by the BIG-EU: - www.big-eu.org [5]. Manufacturers can run tests in their own labs before submitting products. Organizations in North America and Europe worked together to create a unified testing and listing program. For the tests, the functional scope of the devices is defined by the manufacturers and if successful tested - listed by BTL. The standard defines the PICS (Protocol Implementation Conformance Statement) and the BIBBs ( Interoperability Building Blocks) to allow an accurate assessment of interoperability. A classification of devices is described with device profiles. Each device profile (operator workstation, building controller, advanced application controller, application-specific controller, smart actuator, and smart sensor) has a minimum of BIBBs expected of it. BIBBs are definitions of functions which are important to operate and monitor the special objects subdivided into data sharing, alarm and event management, scheduling, trending, device and network management. PICS are provided by manufacturers and give information about devices: 1. The implemented object types, (input, output, schedule.) for the Application, 2. Application services and their role (initiate or execute), 3. Physical media and lower protocol layers, 4. Character sets supported. Vendors and Users There is a steady growing community of vendors, as of May 2, 2007, 255 Vendor IDs have been issued and are distributed internationally from 29 countries [6]. There are ten-thousands of installed systems ranging in complexity from a single gateway to very large office buildings with top-to-bottom native systems, to campus or citywide systems linking multiple buildings in over 82 countries and on all continents of the earth. The benefits of This protocol has been designed specifically for building operation - some functional examples are: * Alarm and event processing, * Scheduling, * Trending, * Command prioritization, * Control logic, * Life safety and security objects. 42

Clima 2007 Wellbeing Indoors Key-note lectures Remember: does not specify the system itself, only provisions for interoperability of different systems or products. 1. doesn't depend on current technology, * is implemented through software, not hardware, * 's objects and services are independent of the underlying network technology, * /WS allow communication between BACS and enterprise applications. 2. has no fixed architecture, * devices can be arranged in flat, bus-like topologies, * devices can be arranged hierarchically. 3. can be implemented in devices of any size: * General purpose, programmable controllers, * Configurable, fixed program controllers, * Application specific controllers, * Workstations and Web servers, * Tool devices and protocol analyzers. 4. can be easily enhanced and improved by extending the object model. 5. There is no charge for the use of - no fees, licenses, royalties, etc.! DISCUSSION A question of responsibility One important motive for the client to contract only one supplier is to be able to assign responsibility in case of faults. It is therefore obvious that all attempts at integration of different functions or systems have been limited to individual manufacturers or suppliers of systems. Faults occurring during the integration and operation of systems, including signaling failure, malfunctions, or other faults, inevitably lead to the question as to who is to account for the resulting damage. Another problem is to allocate the proper share of responsibility for faults or damage to every single supplier involved. External" systems, for instance, can be infinite sources of faults. For this reason, the question of insurance is particularly important, especially where the protection of life and limb is concerned [7]. Combination or integration of security and signaling systems with other systems is only acceptable if the possibility to detect faults, and the possibility to document any external influence on the safety alarm system can be fulfilled. Combination of autonomous systems for safety/security alarm and building automation and control becomes feasible if responsibleminded companies create interfaces ensuring that all external influences on the system can be traced back to their origins. Anyway - whatever the future may have in store with regard to system integration, we should not let ourselves be guided by wishful thinking and idealized notions about technological feasibility. Instead, we should always be aware of the human weaknesses and their impact on the functioning of combined or integrated systems. With regard to project integration, we can normally assume that a trustworthy supplier of "combined systems" assumes the role of the general manager and therefore also ensures the necessary degree of integrity. 43

Clima 2007 WellBeing Indoors Abstract Book ACKNOWLEDGEMENT The BIG-Fi ( Interest Group Finland) made it possible to provide this paper. (ABB, Honeywell, Siemens and VTT). Special thanks to Siemens Building Technologies, Finland, for the great support. REFERENCES 1. ASHRAE. 2004. ANSI/ASHRAE Standard 135 2004, - A Data Communication Protocol for Building Automation and Control Networks, Atlanta: American Society of Heating, Refrigerating, and Air-conditioning Engineers, Inc. 2. ISO 16484-5 Building automation and control systems - Part 5: Data communication protocol, CD-ROM, 2007-03, 3. DIN EN ISO 16484-5 Systeme der Gebäudeautomation - Teil 5: Datenkommunikationsprotokoll (ISO 16484-5:2003); Englische Fassung EN ISO 16484-5:2003, Norm, CD-ROM, 2004-08, (http://www.beuth.de) 4. DIN EN ISO 16484-6 Systeme der Gebäudeautomation - Teil 6: Datenübertragungsprotokoll - Konformitätsprüfung (ISO 16484-6:2005); Englische Fassung EN ISO 16484-6:2005, Norm, CD- ROM 2006-04, (http://www.beuth.de) 5. www.big-eu.org 6. www.bacnet.org. 7. Kranz, Hans R. 2006. Gebäude-Automation 1.4, Karlsruhe Germany: Promotor Verlag, ISBN 3-922420-09-5. 44