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Intelligent Buildings Technology BEM Systems – Architecture [4] Centralized architecture Decentralized architecture Intelligent Buildings Technology BEM Systems – Architecture [5] Intelligent Buildings Technology BEM Systems – Communication [1]    Communication protocols are necessary as communication interfaces between the elements that consist the systems (sensors, actuators, controllers, etc.) Information should be transferred and delivered in a certain way that is defined by the communication protocol The compatibility of each element of the BEM system with the communication protocol is an essential parameter when structuring the system Intelligent Buildings Technology BEM Systems – Communication [2]  Network topologies determine the way the Operator Workstation (OWS) is connected with the various equipment:      Point-to-Point: The simplest approach where the OWS is directly connected with an outstation Star: Like Point-to-Point but more than one units are connected to OWS Bus: The various units communicate independently between them and the OWS The extension of the network is simple Ring: Information is transferred around the ring only in one direction Each unit recognizes if the information is of its own concern, otherwise information bypasses the unit (token-passing protocol) Tree or Hierarchical: Units communicate through a tree topology Intelligent Buildings Technology BEM Systems – Communication [3] Intelligent Buildings Technology BEM Systems – Communication [4] Intelligent Buildings Technology BEM Systems – Communication [5] Intelligent Buildings Technology BEM Systems – Communication [6] Intelligent Buildings Technology BEM Systems – Communication [7] Intelligent Buildings Technology BEM Systems – Sensors  Measurement of solar radiation  Temperature sensors  Humidity sensors  Measurement of wind velocity and direction  Flow metering sensors  Air pollutants measurement sensors (CO, CO2)  Presence/Occupancy sensors Intelligent Buildings Technology BEM Systems – Actuators – Ventilation Intelligent Buildings Technology BEMS – Control of the System  Open loop External Variable  Sensor Controller Actuator Controlled Device Controlled Variable Closed loop Set Point + Controller - Actuator Controlled Device Controlled Variable Sensor Intelligent Buildings Technology BEMS – Control of the System On/Off: There are only states of outputs (e.g in a valve fully opened/fully closed) Intelligent Buildings Technology BEMS – Control of the System Logic programming: The implementation of the control strategy is based on the use of logical rules: IF (Room temperature is over 26C) THEN (Close blinds) AND (Switch fans off)  The connected appliances are controlled mainly by On/Off  Intelligent Buildings Technology BEMS – Control of the System Fuzzy Logic: This kind of control require the synthesis of a large number of parameters and sometimes is quite difficult to predict the “behavior” of the controller The use of fuzzy logic can be efficient for controlling complicated parameters such as thermal comfort Intelligent Buildings Technology BEMS – Control of the System     Neural Networks: The structure of these controllers tries in a certain way to emulate the function of the human brain They are using mainly in non-linear systems The can divided in various layers The 1st layer is composed by the Inputs while the last by the Outputs A layer may includes nodes that connect this layer with nodes in the next layer through weighted links Intelligent Buildings Technology BEMS – Control of the System Intelligent Buildings Technology BEMS – Control of the System Ambient Temperature (T) 32 30 28 26 24 22 20 actual Tvalue predicted T 10 15 hour 20 25 Intelligent Buildings Technology Communication Protocols Intelligent Buildings Technology Communication protocols  Industrial progress in semiconductor development and growing demands by the end user, e.g better control performance, have led towards advanced control systems, known as serial networked control network systems Features of these control systems are:       Distributed intelligence, using microcontrollers Real-time operations are possible Peer-to-peer architecture Memory and software programs are provided at node level Software is implemented in layered protocol stacks The limitations of serial networked control systems lie mainly in network expansion, a limited variety of topologies and transmission media These limitations are overcome by the new generation of distributed control network systems with the following features:      Mixing of communications media (twisted pair, power line, radio, infrared, fibre optics, coaxial) A better, or more complete, implementation of the OSI model with higher reliability of the (growing) network Free topology User-friendly software and available development tools Connectivity units, gateways, bridges, routers and repeaters Intelligent Buildings Technology Communication protocols  With distributed control network systems a major step towards intelligent building automation systems has been made, resulting in:          Lower operating costs Demands for sharing information Improved human environment, especially work place conditions Improved building performance and economy Similar to a factory plant, a public building includes several types of network systems, such as: Building automation systems: responding to external conditions and controlling the internal environment or generating alarms Building management systems: monitoring, managing and storing control data Local area network system: handling information exchange within a company Communication systems: providing links for worldwide communication and data exchange Intelligent Buildings Technology Communication protocols  Building automation systems are used for the following automation services and control tasks:       Heating Ventilation Air Conditioning (HVAC) Lighting and emergency lighting control Power management Security and protection Transport (lifts) These automation services are currently supported by communication protocols such as:         BACNET ARCNET BitBus CAN EIBUS LonWorks PROFIBUS And many other systems based on RS-232, RS-422, or RS-485 communication standards Intelligent Buildings Technology Communication protocols – EIBUS  Founded in 1990 by 15 firms, the European Installation Bus (EIB) Association is now an association of almost 100 electrical installation firms who have joined together for the purpose of bringing about a common standard for installation buses in the market place Their objective for a uniform building management system throughout Europe is achieved by:        Laying down technical directives for systems and products Devising quality rules Drawing up test procedures Making system know-how available to members, subsidiaries and licensees Engaging test institutes to perform quality inspections Granting third parties who pass tests the use of the "EIB" mark Taking an active part in standardization Intelligent Buildings Technology Communication protocols – EIBUS  EIB concentrates unequivocally on home and/or building management This focus permits it to deal with all tasks and challenges within this domain thoroughly and efficiently The European Installation Bus (EIB) is an open, comprehensive system that covers all aspects of Building Automation  Though standardized Bus Access Unit (BAU) building blocks are available from several vendors This means EIB is open: EIB may be implemented by anyone, on any chip or processor platform chosen - both as proprietary implementation for individual products, as well as for OEM BAU's Conformity tests are defined, and EIB Certification is open to all members of the Association  Why "in 0th approximation"? Because EIB embeds the protocol in an encompassing Home and Building Electronics System, with standardized system components (such as the BAUs), network management and interworking standards, with a vendor-neutral tools and programming interfaces for PC's, training for electrical contractors, certifications schemes etc Intelligent Buildings Technology Communication protocols – EIBUS  The European Installation Bus (hereafter referred to as "the Installation Bus" or in short as "the Bus") is designed as a management system in the field of electrical installation for load switching, environmental control and security, for different types of buildings The Installation Bus can be installed in large buildings such as business premises, schools, hospitals, factories and administration premises as well as in domestic residences Its purpose is to ensure the monitoring and control of functions and processes such as lighting, window blinds, heating, ventilation, airconditioning, load management, signaling, monitoring and alarms  The EIB system allows the bus devices to draw their power supply from the communication medium, like Twisted Pair or Powerline (230 V mains) Other devices may, additionally, require power supply from the mains or other sources, as in the Radio Frequency and Infrared media Fig 3.4 draws some usage examples