Building automation

A building management system (BMS ) is defined as the set of monitoring, control, regulation and optimization of building installations. It is thus an important component of technical facility management. The goal is to craft comprehensive functional processes independently ( automatically ) to perform according to predetermined set values ​​( parameters) or to facilitate their operation or monitoring. All sensors, actuators, controls, consumers and other technical units in the building are interconnected. Processes can be grouped into scenarios. The characteristic feature is the decentralized arrangement of the control units ( DDC GA ) and continuous networking via a bus system.

• 3.3.1 control and management systems for remote maintenance
• 3.3.2 Management and automation level
• 3.3.3 automation and fieldbus level
• 3.3.4 Radio buses

• 5.1 ways of building automation (BA )
• 5.2 Advantages and disadvantages 5.2.1 benefits
• 5.2.2 disadvantages

• 6.1 Management level
• 6.2 automation level
• 6.3 Field level

Relation to administrative Facility Management

For the implementation of administrative facility management are a variety of information (base area, type of use, energy demand, etc. ) is required to operated buildings. The support of administrative facility management through information technology is referred to as computer-aided facility management ( CAFM ). The building automation can provide some of the information needed is available in the context of technical facility management. Thus, the software management level or building control systems can be linked to the computer-aided facility management ( BMS). However, the tasks of building automation go beyond the mere provision of information through active management of the technical building equipment far beyond.

System components according to DIN 276

The increasing importance of room automation within the building automation in particular of non-residential buildings is the DIN 276: Building costs since 2006 by, by having ordered the new cost groups. A building automation system thus consists of the subsystems

• Building Management System ( BMS or SCADA also )
• (Plant ) Automation System ( also DDC - GA) including cabinets and
• Room automation system.

In addition to the original meaning of the cost estimate and settlement are the image and the communicative relations of subsystems, with each other. While communication between room automation and process automation system mainly applies to the demand- control of the energy producer, the interfaces of both automation systems serve the management system mainly for the visualization, operation or trending.

Compared to the planar model described below, the DIN grouping omitted because of the increasing convergence of a subdivision in automation and field level; Rather, one finds the functions of both levels equally both within the room automation system as well as in plant automation. Only the management level is maintained as a separate component of the system.

Technological basics

Technical elements

Components in building a system for building automation are:

• Control units DDC GA
• Cabinet
• Field devices such as sensors and actuators
• Room automation system
• Cabling and bus systems
• Servers and Gateways
• Building management system (software on the host computer for the visualization of the systems)

Technical philosophy of building automation

Vendor independence / open systems

These keywords are the key issues for years in building automation. You are required everywhere, but not implemented so right from the manufacturers and torpedoed obvious reasons (sales / market consolidation ). However, some independent companies offer fabrikat neutral building control, through the connection of various substations / DDC GA components is possible.

In building automation we speak of independence from manufacturers, when installing a system that gives the operator the possibility to communicate makes several manufacturers without major problems together (interoperability). The function of the manufacturer is not solved, but only loosened. Where there is the oddity that there are price lists for various DDC GA manufacturers for the DDC GA components, but are generated for the gateway according to project political prices.

The dependence on the installer regarding the existing facilities, the maintenance according to VDMA, or repair damage persists because it is illusory aspects of cost usually to replace a controller ( DDC GA) in the cabinet against another. In new buildings or extensions but tender freedom is made possible, thus creating investment. In addition, there is the option to display additional properties that were previously regulated and monitored separately due to different manufacturers.

Networking

Nowadays, the trend is away not only in the classical building automation with the art direction in multimedia networking, but also about different trades.

In the white goods, there is a persistent tendency towards "networked home appliances ", mostly over powerline solutions. Thus developed Bosch Siemens Home Appliances serve @ Home, Miele Miele @ home, there are products and takes place in Switzerland one ZUG-Home of the V- train. The presentation of the network or the devices are controlled in most instances through a web browser, and is sometimes integrated with other building automation solutions, so that the cycle is complete to consumer electronics and the new media.

It looks similar ( Consumer Electronics ) in the Red (heating equipment) and brown goods. The intelligent networking in building automation is driven by technological progress, combines the different areas ( brown goods, white goods, red goods ). Increasing flexibility of the systems and structures falling costs increase demand for appropriate solutions - both on a professional as well as private sources.

The goal of networking at the White, Brown and Red Ware is always to increase the added value, the device shall and create new (remote) control options. The underlying technology is usually LON, UPnP or EHS (Powerline ) where the embedded software stack often to OSGi (Java) touches. EIB is here usually integrated as another protocol stack with, so that a holistic solution is formed with a uniform operation.

Based technologies for building automation

Control and management systems for remote maintenance

For use mostly come proprietary solutions, for example for remote management of the local OSGi systems described below.

Management and automation level

Automation and fieldbus level

Radio buses

Several manufacturers also offer radio-based systems with their own protocols. It is advantageous to the easy upgrading and independence of all lines, which is why, for example, Light switch, even subsequently, can be placed anywhere. In addition, wireless systems are compared to conventional bus systems are often significantly cheaper to buy. Disadvantages of such systems are often because they do not or only partially (eg only on and off ) are compatible with each other mostly.

Here the most important:

• EnOcean
• ZigBee
• Z -Wave
• Wlan
• Bluetooth

Other bus systems used for building automation

• BACnet
• Controller Area Network (CAN)
• Digital Addressable Lighting Interface ( DALI)
• EtherCAT
• Ethernet
• EIA-485
• Interbus
• Modbus
• Profibus
• PLC-BUS
• Site Control Local Area Network - SCLAN
• Local Control Network ( LCN)
• EBus
• OpenTherm
• X10

Home automation

Home automation ( home automation ) or home automation is that part of the building automation field, which is aligned to the realities of private houses and the special needs of its inhabitants. While in the automation of public buildings, industrial buildings, etc. are the achievable energy and labor savings in the foreground, these are in home automation, the increased living comfort, the safety of the residents and the ability to track multiple residences. Main difference to the overall building automation is the particular importance of a comfortable user interface ( visualization). There is often in the home automation functions in building automation - if at all - only play a minor role (eg Entertainment, automatic plant watering or pet feeding, lighting, programs for parties, etc. ).

Opportunities and risks

Opportunities for building automation (BA )

• Demand, time of day or season - and movement-dependent switch or dim lighting
• Control heating, ventilation or air conditioning needs and timely
• Control shading devices in response to sunlight and wind time and demand
• Increase security by monitoring door and window contacts, and motion detectors
• Implement access control systems
• Capture and display all control operations in the building centrally
• Switch or dim with radio or infrared remote control
• Remote monitoring and control via the telephone network or via the Internet ( remote operation )
• Consumption data acquisition of heat meters, water meters, gas meters and electric meters.
• Load control based on the consumption data collection by sequentially activating lights
• Controlling media devices, multi-room systems in the training, seminar and media rooms
• Control of electrical devices of everyday life, such as coffee or radio
• Simulation of presence increased security

Pros and Cons

Benefits

• Energy consumption reduction through intelligent control
• Gain in comfort through intelligent control: for example, can be made to a key press a predefined lighting situation without multiple lamps must be individually switched or dimmed; or by logical combinations of switching states alternatively defined actions can be triggered
• Protection against break-ins through presence simulation
• Security for the residents by alerting the occurrence of critical situations
• Monitoring by an external security service by automatic alarm forwarding

Disadvantages

• Higher initial cost compared to normal building installation. For one thing, but the cost is amortized often through energy savings in the operation, on the other hand are impossible or much more expensive many features with classical building installation.
• At high complexity qualified personnel necessary for the operation of the plants.
• Increased dependence on the installer or DDC GA manufacturers of the equipment, as some builders are the manufacturers of DDC - GA- components simultaneously. It is therefore important to ensure that all documents, including the current programs in the DDC - GA- components to it, otherwise the subsequent expansion of the systems must always be carried out by the installer. Alternatively, standardized bus systems with certified products (EIB, KNX) use to ensure a great vendor diversity and usually also interchangeability of components.
• Increased susceptibility to failure compared to normal building installation due to hardware or software errors. In systems with centralized control, this can have a single point of failure present, and, if there is no redundancy, have a defect or misconfiguration the failure of the entire system result.

Logical levels in building automation

The building automation ( functional) divided into three levels. The field level, the automation level and the management level.

The classical division of the planes can be seen in the picture. Due to the rapid development of microprocessors in recent years, the previous classical division of the field, automation and management level is becoming more blurred. It moves more intelligence in the sensors and actuators so that they are now connected directly to the fieldbuses of the DDCs. Partly have field devices on management functionality. Furthermore, wanders through the use of so-called residential gateways also more local intelligence in the automation level, whereas the management level is partially divided into local and remote management. This makes itself felt above all that requirements differ in the home ( single-family ) very different from those in the professional sector (office building).

Management level

As a management level, the plane is referred to, by which the assets are monitored and optimized in their operation. The visualization of historicist and statistically processed data is one of them. At the management level, special software, the building control system is applied. There are several vendor- dependent systems, which have their pros and cons. As a vendor- independent interfaces for management systems are here to OPC and BACnet call, with BACnet also works on the automation level (native BACnet).

It is possible at the management level to pick up on the gateway vendor lock-in existing systems with proprietary bus systems. For this purpose, however, the manufacturer's cooperation is necessary for most systems.

Depending on the application the management level in local and remote management can be divided, with so-called residential gateways take over the local management either completely self-sufficient, or may form a component thereof. The Remote Management in turn sets from a central location on the local components, allowing for example remote control via secure Internet connections.

Often misunderstood as " Management" there are functions for the operation of building automation. These functions are independent of each plane in question (according to DIN EN ISO 16484 ). With the operating functions GA systems are controlled and visualized information for the operator.

Automation level

For the exchange of data on the automation level between the DDCs, despite standardization still many proprietary bus systems in use. However, it is by the pressure of the market, a trend towards multi-vendor exchange of information observed ( interoperability). DDC GA components that work with these open systems at the automation level, but are far more expensive.

On the automation level are particularly BACnet and LON ( Local Operating Network) to name as manufacturer-independent bus systems. BACnet and LON is used by large companies preferably in commercial buildings. The aim is to realize the management of major building systems such as office buildings, hospitals or airports with a real open standard.

Due to the vendor market -oriented public little reliable information on the number of implemented systems are possible. Only the organized within the VDMA -AMG manufacturers have access to the very detailed " VDMA statistics" that provides reliable market data since 1987.

There are also radio systems for retrofitting if no new cables to be drawn.

As an alternative to bus systems and programmable logic controllers ( PLCs) are used in building automation. With the help of bus couplers Mixed forms are also possible.

Based on powerful control controllers in the cabinet are establishing themselves in the last few years building OSGi-based operating systems like PLC systems, however, here no programming is required. All functionality will be picked via a management software.

Field level

As a field level, the wiring of sensors and actuators is designated by the DDC GA components. The interfaces to the sensors are very simple, since the sensors are usually connected directly to the inputs of the DDC. It evaluates the DDC GA component with temperature sensors, zBsp. PT100, NTC1K8 or NTC10K, the resistance changes from representing the measured value .. For active sensors, such as for example the pressure sensors is an analog standard signal of 0 /4 to 20 mA or 0 to 10 V transfer which represents the measured value. The digital inputs are working with floating contacts and S0 interfaces.