Building Management System to Save Energy

Building Management ashes to Save Energy1. Introduction of BMSBuilding Management System (BMS) is to regard and allwheresee building run schemas in an efficient way by centralizing the control of individual systems ( 1.1). The systems embarrass HVAC, Fire Services Lift, Escalator, Lighting, Electrical Distri furtherion, Steam savoury Water, and Plumbing Drainage.The main function of BMS is centralized control monitoring and fault management. So it has another name call Central Control and Monitoring System (CCMS). The other functions are enhance interface connectivity in the midst of systems, service rejoinder to customer, operator control of systems and graphical display to make the control of system more(prenominal) drillrs friendly. Improve energy efficiency and operational efficiency. Allow capacity for future upgrades expansions and automation. And related system Building Automation System (BAS) will be delectation on BMS.2. Basic BMS Design3- aims BMS Arc hitecture ( 2.1)l Management Level User bear configure and monitor plant performance. Anticipate future trends, remediate efficiency, and analyze management report.l Automation / Controller Level The location with groovyest technical control requirement, and contrastingiate one from others. Controllers automatically perform their tasks from I/P and to O/P. Controllers bum communicate with each other (Peer-to-Peer). Event based operation. The contrivances can function at the highest efficiency and no repetitive info is transmitted. Controllers lone(prenominal) react with the Management Level when plant goes out of limits, and adjustments are do through a expenditurer interface.l national / Floor Level Information is gathered through sensors and other intelligent devices. The information will be sent back to the controllers.Third party equipment is integrated into the Automation and Field levels with control at the Management level.Centralized ArchitectureCentrally cont rolled system ( 2.5) A control system in which transmitting is to a central estimator and the reliance of all controls on a central computer.Distributed ArchitectureDistributed control ( 2.6) A control system in which control computations and intelligence are made at different locations and the result coordinated.System ArchitectureThe constraints of BMS are ne bothrk expansion, the contain variety of topologies and transmission media. The solutions are mixing of communicating media (twisted brace, power line, radio, infra-red, emblem optics, coaxial). Complete implementation of OSI model. Using free topology, user-friendly software and development cost.System TopologyTopology affects system redundancy, communication protocol and system response quantify. The common system topologies such as Bus, Star, Tree, Ring and Mesh.Bus Topology ( 2.7) All devices are connected to a central cable, call the bus or anchorman. The advantage is much less cabling requirements. The brands victimization include Ethernet, Profitbus, ControlNet, LonWorks.Star Topology ( 2.8) All devices are conned to a central hub. Star lucres are comparatively painless to install and manage, but bottlenecks can occur because all selective information must pass through the hub. Cable fault affects one device only. But communication hub fault affects all devices. The brands apply include Ethernet, Profitbus, ControlNet, LonWorks.Tree Topology ( 2.9) The topology combines characteristics of linear bus and star topologies. It consists of groups of star-configured workstations connected to a linear bus backbone cable. Tree topologies allow for the expansion of an existing network, and enable schools to configure a network to meet their needs. Device at the highest point in the hierarchy controls the network. The brands development include Ethernet, Profitbus, ControlNet, LonWorks.Ring Topology ( 2.10) All devices are connected to one another in the shape of a closed loop, so that ea ch device is connected directly to two other devices, one on either side of it. Same as bus network with both edges connect. The brands using include Token Ring, FDDI, Profitbus.Mesh Topology (Fig 2.11) Network topology which combines more than one basic topology such as bus, ring, or star. Good for redundancy. It will use lots of cable to connect every device with every device.Considerations in Topology Layout for automating building with vast amount of points require well-designed network segmentation, in holy rove to achieve a good performance infrastructure. Well designed structured network by using repeaters, bridges or even better using routers to improve network reliability and simplify network troubleshooting. Some reasons why segmenting a network is important Isolation of individual network segments in order to limit the propagation of a single fault to one segment and prevent this single fault from spreading out oer the entire network. variant nodes demand different c ommunication media and different network speeds but they all need to communicate with each other, which requires and interconnection between the different networking media. Increase the number of possible nodes in a single network and increase the number of possible nodes in a single network. Keep local anesthetic business indoors one segment in order to avoid network traffic oerload conditions which will make service like HVAC, atonicing malfunction.BMS ConfigurationsThere are three types configurations using in BMS1. Conventional configuration Server workstations daisy chained with DDCs (usually using RS-485). classifiable RS-485 Controller Level network ( 2.14) relatively low bandwidth ( just about 9600 bps). The limited nodes around 100, and the distance is lower than 1200m. Only for data transmission.Controller Level Network2. Ethernet-Based configuration Use Ethernet as transmission media. Servers, Workstations and DDCs on the like Ethernet platform. Typical Ethernet- Based Network ( 2.15) with high bandwidth (typical 1Gbps backbone). Use IP Technology means open platform for various coatings. Virtually no distance limitation. Always use for data, junction video systems.Ethernet-Based Network3. Hybrid configuration ( 2.16) Non-hierarchy architecture with combination of different independent networks and interfaces. Various network topologies.Hybrid ConfigurationNetworking ProtocolProtocol ( 2.17) is a set of rules, which allows computer/controllers/devices to communicate from one to another. Proprietary Protocols developed by systems or computer manufacture to communicate to their OWN hardware and software all over a recommended network. Open Protocols opening up protocols means disclosing procedures, structures, and codes and allowing other system developers to write interfaces and share data on their network. Acceptance of an open protocol depends on its quality, features, and services provided.2.17 ProtocolThe OSI Seven story Model ( 2. 18) severally social class has a defined set of functions. The model provides a useful common theatrical role to communicate protocol. Most communication protocols including those used in our field today use either all or some of the seven moulds of the OSI model.1. Network-capable Applications produce DATA.2. Each protocol layer adds a header to the data it receives from the layer above it. This is called encapsulation. Encapsulated data is transmitted in Protocol Data Units (PDUs). There are founding PDUs, Session PDUs, behave PDUs and so on3. PDUs are passed down through the stack of layers (called the stack for niggling) until they can be transmitted over the bodily layer.4. Any layer on one machine speaks the equivalent language as the same layer on any other machine, and therefore can communicate via the Physical layer.5. Data passed upwards is unencapsulated before being passed farther up.6. All information is passed down through all layers until it reaches the Physi cal layer.7. The Physical layer chops up the PDUs and transmits the PDUs over the wire. The Physical layer provides the real physical connectivity between machines over which all communication occurs.2.18 OSI Seven Layer ModelThe Physical layer provides for physical connectivity between networked devices. Transmission and receipt of data from the physical medium is managed at this layer. The Physical layer receives data from the Data Link Layer, and transmits it to the wire. The Physical layer controls frequency, amplitude, phase and passage of the signal used for transmitting data, and performs demodulation and decoding upon receipt. Note that for two devices to communicate, they must be connected to the same type of physical medium (wiring). Ether to Ether, FDDI to FDDI etc. Two end stations using different protocols can only communicate through a multi-protocol bridge or a router. The physical layer is responsible for two jobs1. discourse with the Data link layer.2. Transmissio n and receipt of data.The Datalink Layer is the second layer of the OSI model. The datalink layer performs various functions depending upon the hardware protocol used, but has four primary functions1. COMMUNICATION with the Network layer above.2. SEGMENTATION of upper layer datagrams (also called packets) into frames in sizes that can be handled by the communications hardware.3. BIT ORDERING. Organizing the manakin of data turn of eventss before transmission (packet formatting)4. COMMUNICATION with the Physical layer below.This layer provides reliable transit of data across a physical link. The datalink layer is pertain with physical addressing, network topology, physical link management, error notification, ordered delivery of frames, and flow control.Network Layer establishes and terminates connections between the originator and recipient of information over the network. Assign unique addresses to each node on the network. The addresses identify the beginning and end of the dat a transmission packets. Outbound data is passed down from the Transport layer, is encapsulated in the Network layers protocol and then sent to the Datalink layer for segmentation and transmission. Inbound data is de-fragmented in the correct order, the IP headers are removed and then the assembled datagram is passed to the Transport layer. The Network layer is concerned with the following(a) primary functions1. Communication with the Transport layer above.2. Management of connectivity and routing between hosts or networks.3. Communication with the Datalink layer below.Transport Layer maintain reliability on the network and enhances data integrity by delivering error-free data in the proper sequence. It may use a variety of techniques such as a Cyclic Redundancy Check, windowing and acknowledgements. If data is lost or damaged it is the Transport layers responsibility to recover from that error. Functions1. Communicate with the Session layer above.2. get hold errors and lost data, retransmit data, reassemble datagrams into datastreams3. Communicate with the Network layer below.The session layer tracks connections, also called sessions. For example keep track of multiple file downloads bespeak by a particular FTP application, or multiple telnet connections from a single terminal client, or web page retrievals from a Web server. In the World of TCP/IP this is handled by application software addressing a connection to a remote machine and using a different local port number for each connection. The session performs the following functions1. Communication with the Presentation layer above.2. Organize and manage one or more connections per application, between hosts.3. Communication with the Transport layer below.The Presentation layer handles the changeover of data formats so that machines can presentdata created on other systems. For example handle the con translation of data in JPG/JPEG format to Sun Raster format so that a Sun machine can display a JPG/JPEG image. The Presentation layer performs the following functions1. Communication with the Application layer above.2. Translation of standard data formats to formats understood by the local machine.3. Communication with the Session layer below.The application layer is the application in use by the user. For example a web browser, an FTP, IRC, Telnet client other TCP/IP based application like the network version of Doom, Quake, or Unreal. The Application layer provides the user interface, and is responsible for displaying data and images to the user in a recognizable format. The application layers job is to organize and display data in a human compatible format, and to interface with the Presentation layer.Message Frame FormatFig 2.19 Message Frame FormatMaster-Slave Protocol (2.20) The control station is called master device. Only master device can control the communication. It may transmit messages without a remote request. No slave device can communicate directly with another slave device.2.20 Master-Slave ProtocolPeer-to-Peer Protocol (2.21) All workstations are ladened with the same peer-to-peer network operating system. Each workstation configured as service requester (client), service provide (server), or even BOTH.2.21 Peer-to-Peer ProtocolClient-Server Protocol (2.22) Client workstation are loaded with specialized client software. Server computers are loaded with specialized server software designed to be compatible with client software.2.22 Client-Server ProtocolThe CSMA/CE Protocol is designed to provide fair admission charge to the shared channel so that all stations get a chance to use the network. After every packet transmission all stations use the CSMA/CD protocol to determine which station gets to use the Ethernet channel next. CSMA/CD likes a dinner party in a dark room Everyone around the table must listen for a period of quiet before speaking (Carrier Sense). Once a space occurs everyone has an equal chance to say something (Multiple Acce ss). If two people start talking at the same instant they detect that fact, and quit speaking (Collision Detection). IEEE 802.3 standard covers CSMA/CD.Switched Ethernet nodes are connected to a switch using point-to-point connections, When a frame arrives at the switch, the control logic determines the transmit port. If the transmit port is busy, the received frame is injectd in the queue which is a First-in First-out (FIFO) queue. The memory to store pending frames is guarded from a shared memory pool. In case the memory is full, the received frame is dropped.Networking CablesCopper wire pairs are the most basic of the data media. Two wire untwisted pairThe insulated wire conductors run in parallel, often in a moulded, flat cable. Normally used over short distances or at low bit pass judgment, due to problems with crosstalk and spurious noise pickup. Performance in multiple conductor cables is enhanced by dedicating every second cable as a ground (zero volt reference), and by the use of electricallybanetworkced signals.1. A single wire is used for the signal transmission/reception2. A common reference level/point is existed between the transmitter and receiver3. It is the frankst connection technique but it is sensitive to noise, interference, loss, and signal thoughtfulness4. It is suitable for short distance and low data rate application (Normally less than 200Kb-meter/s) Twisted twosomeThe insulated conductors are twisted together, leading to better electrical performance and significantly higher bit rates than untwisted pairs. UTP is unshielded, like telephone cable, whilst STP is shielded and capable of higher bit rates. Systems using banetworkced signals obtain the highest bit rates.1. Twisting or wrapping the two wires around each other reduces induction of outside interference2. 1 to 5 twists per inch is quite typical Cheap and moderate bit rate applications3. For a few km distance the bit rate can be up to 10Mb/s, and 100Mb/s can be achie vable for short distance applications like 100m2.23 Two wire untwisted pair and Twisted PairUnshielded Twisted Pair (UTP)Composed of two of more pairs of wires twisted togetherNot shieldedSignal protected by twisting of wiresImpedance of 100WRecommended conductor size of 24 AWG2.24 Unshielded Twisted PairCat5e 100MHz ANSI/TIA/EIA-568-B.1Cat6 250MHzCat7 600MHzUndercarpetSusceptibility to damageLimited flexibility for MACs (move, add and change)Distance limit of 10mAvoid in high traffic areas, heavy furniture locations, cross undercarpet power on top at 90 degrees2.25 Cat3, Cat5e and Cat6 CableScreened Twisted-Pair (ScTP)Characteristic electric resistance of 100 WFour pair 22-24 AWG substantial conductorsMylar/aluminum typeface around all conductorsDrain wire that must be grounded2.26 Screened Twisted-PairShielded Twisted Pair (STP)Composed of two pairs of wiresmetallic element braid or sheathing that reduce electromagnetic interference (EMI)Must be groundedCharacteristic impedance of 150 WConductor size is 22 AWGElectrical performance is better than UTP (300MHz bandwidth)More expensiveHarder to handle thick and heavy2.27 Shielded Twisted PairCoaxial Cable (Coax) Composed of insulated bone marrow conductor with braided shied. It provides high degree of protection against EMI.Because the electrical field associated with conduction is entirely carried inside the cable problems with signal radiation are decrease very little energy escapes, even at high frequency.There is little noise pick up from external sources. Thus, higher bit rates can be used over longer distances than with twisted pairs2.28 Coaxial Cableserial publication 6 (Video)Characteristic impedance of 75 ohmsMylar/aluminum sheath over the dielectricBraided shield over the mylar18 AGW solid-center conductor2.29 Series 6Series 11U (Video)Characteristic impedance of 75ohmsMylar/aluminum sheath over the dielectricBraided shield over the mylar14 AWG solid-center conductor or 18 AWG stranded-center co nductor2.30 Series 11USeries 850 ohms characteristic impedanceMultiple mylar/aluminum sheath over the dielectricMultiple braided shield over the mylar11 AWG solid-center conductor2.31 Series 8Series 58 A/U50 ohms characteristic impedanceMylar/aluminum sheath over the dielectricBraided shield over the mylar20 AWG solid-center conductor2.32 Series 58 A/UFibre Optics Higher bandwidth and much lower signal loss than copper conductors. It used in the backbone or in horizontal runs of huge control network.The data is carried as pulses of light from a laser or high-power LED.Optical fibre is non-electrical, hence is completely repellent from electrical radiation and interference problems. It has the highest bit rate of all media.The fibre consists of an inner glass filament, contained inside a glass cladding of lower deflective indicant, with an outer protective coating. In a step powerfulness fibre, there is a sudden transition in refr active index. A graded index fibre has a gradual transition from high to low index, and much higher performance.Most common fibres are multimode, where the inner fibre is larger than the wavelength of the light signal, allowing multiple paths to exist, and some dispersion to limit the obtainable bit rate. In single mode fibres, the inner fibre is very thin, and extremely high bit rates (several Gbps) can be achieved over long distances.2.33 Fibre OpticsMultimode Fibre Composed of a 50 or 62.5 micrometer caliper core and 125 micron cladding. It commonly used in horizontal and intrabuilding backbones. It has distance limitation of 2000m. Often uses a light-emitting diode (LED) light source.The center core is much larger and allows more light to enter the characterSince there are many paths that a light ray may follow as it propagates down the fiber, large time dispersion may occur which results in short distance applications or bandwidth reductionBecause of the large central core, it is easy to couple light into and out of the th is type of fiberIt is inexpensive and simple to manufactureTypical value 62.5/125Multi-Mode Graded IndexIt is characterized by a center core that has non-uniform refractive indexThe refractive index is maximum at the center and decreases gradually towards the outer edgeThe performance is a compromise between single-mode step index fiber and multi-mode step index fiber2.34 Multi-Mode FibreSinglemode Fibre It composed of a 6 or 9 micron core and 125 micron cladding (say8/125 or 9/125). It used for distances up to 3000m. It uses a laser light source.Small core diameter so that there is essentially only one path that light may Take care,as it propagates down the fiber There is minimum time dispersion because all rays propagating down the fiber with the same delay time and results in wider bandwidth (i.e. high bit rate) Because of the small central core, it is arduous to couple light into and out of the this type of fiber It is expensive and difficult to manufacture Typical value 9/1252 .35 Singlemode Fibre2.36 LAN Media Technology AnalysisOpen SystemThe definition of open system is that system implements sufficient open standards for interfaces and services. It is supporting formats to enable properly engineered components to be utilized across a wide range of systems and to interoperate with other components. And that system in which products and services can be mixed and matched from set of suppliers and supports free exchange of information/data between different systems without inserting gates or proprietary tools. Some benefits from InteroperabilityDevices can be shared among different subsystems.Reduce cost, shorten installation time, and reduce complexity as parts are being reduced.Devices in different subsystems can move with each other therefore, new breed of applications can be created easily.Owners can choose the best-of-breed products from different manufacture.Elimination of gateway dependency, especially during system upgrade.Allow move-add-change relatively easy, hence lower life-cycle costs.The characteristics of open system are well defined, widely used, preferably nonproprietary interfaces/protocols Use of standards which are developed/adopted by accepted standards bodies or the commercial market place and definition of all aspects of system interfaces to facilitate new or additional systems capabilities for a wide range of applications.The different between proprietary protocols and open protocols For Proprietary protocols, most manufactures have their own proprietary protocols within their systems, so no communication between Systems unless a gateway is deployed. For open protocols, it allows systems of different manufacturers to communicate. Systems communicate with each other.2.1 BMS Open System ModbusA high-level protocol for industrial networks developed in 1979 by Modicon (now Schneider Automation Inc.) for use with its PLCs. It is providing services at layer 7 of the OSI model. Modbus defines a request/response message structure for a client/server environment. It is the most commonly gettable means of connecting industrial electronic devices. Several common types of Modbusl Modbus RTUn A compact, binary representation of the data.l Modbus ASSIIn Human readable more verbose.l Modbus/TCPn Very similar to Modbus RTU but is transmitted within TCP/IP data packets.2.37 Modbus2.2 BMS Open System ARCentAttached preference Computer NETwork (ARCnet) was founded by the Data point Corporation in late 1970s. ARCnet was one of the topologies used early on networking and is rarely used as the topology of choice in current LAN environments. ARCnet, however, still is a solid, functional and cost effective means of networking. Each device on an ARCnet network is assigned a node number. This number must be unique on each network and in the range of 1 to 255. ARCnet manages network access with a token passing bus mechanism. The token (permission to speak on the network) is passed from the lowest number node to higher number nodes in ascending order. pull down numbered addresses get the token before the higher numbered addresses. Network traffic is made more efficient by assigning sequential numbers to nodes using the same order in which they are cabled. Choosing random numbers can create a situation in which a node numbered 23 can be a whole building away from the next number, 46, but in the same room as numbers 112 and 142. The token has to transit in a haphazard manner that is less effective than if you numbered the three workstations in the same map sequentially, 46, 47, and 48, and the workstation in the other building 112. With this configuration, the packet stays within the office before venturing on to other stations. A maximum time limit of 31 microseconds is allotted for an ARCnet signal. This is also called a time-out setting. Signals on an ARCnet can travel up to 20,000 feet during the 31-microsecond default time-out period. You can sometimes extend the range of an ARCnet by increasing the time out value. However, 20,000 feet is the distance at which ARCnet signals begin to severely degrade. Extending the network beyond that distance can result in unreliable or failed communication. Therefore, the time-out parameter and cabling distance recommendations should be increased only with great caution.An ARCnet network is used primarily with either coax or twisted pair cable. Most older ARCnet installations are coax and use RG-62 A/U type cable terminated with 93 Ohm terminators. Twisted pair (UTP) installations are newer and use stranded 24 or 26 gauge wire, or solid core 22, 24, or 26 gauge type cable terminated with 100-Ohm terminators. Many ARCnet networks use a mix of both coax and UTP cabling. UTP cable is simple to install and provides a reliable connection to the devices, whereas coax provides a means to span longer distances. Typical ARCnet installations are wired as a star. ARCnet can run off a linear bus topology using coax or twisted pa ir as long as the cards specifically support BUS. The most popular star-wired installations of ARCnet run off two types of hubs1. Passive hubs cannot amplify signals. Each hub has four connectors. Because of the characteristics of passive hubs, unused ports must be equipped with a terminator, a connector containing a resistor that matches the ARCnet cabling characteristics. A port on a passive hub can only connect to an active device (an active hub or an ARCnet device). Passive hubs can never be connecte