About Intelligent Buildings <br />The concept of intelligent buildings originated in the United States at the end of this century. The first intelligent building was built in Hartford, USA in 1984. China only started developing intelligent buildings in the 1990s, but its rapid development has attracted worldwide attention.
Intelligent buildings are an inevitable product of the information age, and the level of intelligence in buildings gradually increases with the development of science and technology. The main indicators of scientific and technological development in the world today are 4C technologies (Computer, Control, Communication, and CRT display). Integrating 4C technologies into buildings and establishing a comprehensive computer network within them enables the building to become intelligent. However, 4C technologies are merely the structuring and systematization of intelligent buildings.
Intelligent buildings should be:
"By optimizing the design of the four basic elements of a building—structure, systems, services, and management—and the intrinsic connections between them, intelligent buildings provide an elegant, comfortable, convenient, and highly secure environment that is both cost-effective and efficient. Intelligent buildings can help building owners, property managers, and owners realize that they are getting the maximum return on their investment in areas such as expenses, living comfort, business activities, and personal safety."
Intelligent building structures consist of three major systems: Building Automation System (BAS), Office Automation System (OAS), and Communication Automation System (CAS).
II. Introduction to Building Automation Systems <br />Building Automation Systems (BAS) are an indispensable part of intelligent buildings. Their task is to monitor and control energy use, environment, traffic and safety facilities within the building to provide a safe, reliable, energy-saving and comfortable working or living environment.
III. Composition and Basic Functions of Building Automation Systems:
Building automation systems (BAS) typically include subsystems such as HVAC, water supply and drainage, power supply and distribution, lighting, elevators, fire protection, and security. According to Chinese industry standards, BAS can be further divided into equipment operation management and monitoring subsystems and fire protection and security subsystems. Generally, these two subsystems should be considered together within the BAS. If the fire protection and security subsystem is set up independently, it should still establish communication with the BAS monitoring center to ensure that operational control can be transferred as agreed upon in the event of a disaster, enabling integrated and coordinated control.
The basic functions of building equipment automation systems can be summarized as follows:
(1) Automatically monitor and control the start and stop of various electromechanical equipment, and display or print the current operating status.
(2) Automatically detect, display, and print the operating parameters and their changing trends or historical data of various electromechanical equipment.
(3) Automatically adjust various equipment according to external conditions, environmental factors and load changes to ensure that they always operate in the best condition.
(4) Monitor and handle various accidents and emergencies in a timely manner.
(5) To achieve unified management and coordinated control of various mechanical and electrical equipment in the building.
(6) Energy management: metering and charging for water, electricity, gas, etc., and realizing the automation of energy management.
(7) Equipment management: including equipment files, equipment operation reports and equipment maintenance management, etc.
IV. Principles of Building Automation Control Systems
The building control system adopts a distributed control system (DCS) based on modern control theory. Its characteristic is "centralized management and decentralized control," meaning that microcomputer control devices (DDCs) distributed at the controlled equipment locations in the field complete the real-time detection and control tasks of the controlled equipment. This overcomes the shortcomings of centralized computer control, such as the high concentration of risks, and the limitations of conventional instrument control functions. The central management computer installed in the central control room has CRT display, print output, rich software management, and strong digital communication capabilities. It can perform centralized operation, display, alarm, printing, and optimized control tasks, avoiding the difficulties in human-machine interaction and unified management inherent in decentralized instrument control, thus ensuring that the equipment operates in optimal condition.
V. Development History of Building Automation System Equipment and Introduction to Related Products
Building automation systems have gone through four generations of products to date:
First generation: CCMS Central Monitoring System (product of the 1970s)
The Building Automation System (BAS) evolved from an instrumentation system into a computer system. A central station was constructed using a computer keyboard and CRT monitor. Printers replaced recording instruments. Data collection stations (DGPs) scattered throughout the building (connecting sensors and actuators) were connected to the central station via a bus, forming a centrally monitored automation system. The function of each DGP station was simply to upload information from field devices and issue control commands to the central station. A central computer controlled the entire system. The central station collected information from each DGP station, made decisions, and completed the control of all equipment. Based on the collected information and energy meter data, the central station performed energy-saving control and regulation.
Second generation: DCS distributed control system (product of the 1980s)
With the development and cost reduction of microprocessor technology, DGP substations were equipped with CPUs, evolving into Direct Digital Controllers (DDCs). DDC substations equipped with microprocessor chips can independently complete all control tasks, possessing comprehensive control and display functions, energy-saving management capabilities, and the ability to connect printers and install human-machine interfaces. A distributed system (BAS) consists of four levels: field, substation, central station, and management system. The main characteristic of a distributed system is that it only has two types of contact points: the central station and the substations. The central station performs monitoring, while the substations perform control. The substations are completely autonomous and independent of the central station, ensuring system reliability.
Third generation: Open distributed system (product of the 1990s)
With the development of fieldbus technology, DDC substations connect the input/output modules of sensors and actuators, applying ON fieldbus to extend from the substation to the field equipment, forming a distributed input/output field network layer. This makes the system configuration more flexible. Due to the openness of onWorks technology, the substations also have a certain degree of open scale. The BAS control network then forms a three-layer structure: the management layer (central station), the automation layer (DDC substations), and the field network layer (ON).
Fourth generation: Network integrated system (21st century product)
With the establishment of enterprise networks (Intranets), building equipment automation systems will inevitably adopt Web technology and strive to occupy an important position in the enterprise network. The BAS central station embeds a Web server, integrates Web functions, and uses web pages as its working mode, making the BAS and Intranet an integrated system.
Network integration (EDI) is a building equipment automation system that uses web technology. It has a set of management software that includes security systems, electromechanical equipment systems and fire protection systems.
The EBI system provides a variety of comprehensive open technologies to meet the needs at different levels, enabling integration at all levels, from the field level and automation level to the management level. The EBI system achieves the integration of management and control systems.
Currently, the largest and most influential building equipment suppliers include Honeywell (USA), Johnson Controls, KMC, and Siemens (Germany).
Conclusion
Building automation control technology is still an emerging field in my country. With the emergence of more intelligent buildings, more advanced technologies will be added to this field, making it more mature and complete.
Brief introduction of the systems and functions of several major building equipment suppliers:
Johnson Controls Metasys Systems
Metasys System Architecture and Hardware Description To build a smart building, a high-quality building automation system is indispensable. The system architecture of JOHNSON CONTROS' Metasys system is as follows:
JOHNSON CONTROS' Metasys building automation system consists of a central operating station (OWS), network controllers (NCU), and direct digital controllers (DDC). The central operating station and network controller nodes are connected via an Ethernet network (N1 network). Ethernet/IP uses standard network hardware to efficiently transmit information between the network controller and user operating stations. Meanwhile, the DDCs installed throughout the building are connected to the network controller via a fieldbus (N2 network), maintaining close communication with other DDCs on the network controller and the central operating station. Sensors and actuators on the field monitoring equipment are connected to these DDCs, thus achieving distributed control and centralized management.
The following provides a detailed description of each of these hardware devices:
1.1 Communication Network The most common connection method between the operator station and the network control unit is the N1 communication network. This structure uses Ethernet technology and communicates over the N1 line through an Ethernet card (network interface card).
Network Setup: The N1 network can be configured as a bus, star, or hybrid topology. This allows for convenient and economical installation and expansion of the N1 network.
N1 networks can use coaxial cable, twisted pair, fiber optic cable, or a combination thereof. The NCU and operator station can directly support coaxial cable and can easily connect fiber optic loops with adapters. The maximum distance for each N1 network segment depends on the medium used and the number of nodes on the network. Active splitters can be used to extend the length of the connections. The maximum distance between two nodes can reach 6.4 kilometers.
The open architecture and interconnectivity of ETHERNET enable its widespread use in industrial and building automation. Numerous third-party vendors support this standard and offer ETHERNET devices, such as splitters and application software. This means that products from different vendors are directly interchangeable, giving users more product choices and reducing reliance on any single vendor.
The N1 network handles various communication types, including database uploads and downloads, commands to field devices, and status messages. Each node has dynamic data access capabilities, meaning that all data can be monitored or controlled from any workstation or NCU on the N1 network.
Dynamic Data Access: While many systems only allow limited data classification, the Metasys system allows free communication between each component on the N1 bus. This is a unique feature of the Metasys system—dynamic data access—which accelerates the transmission of large amounts of information.
The operation of the dual on-Works N2 bus is monitored by the NCU on the on-Works N2 network. If one line fails (i.e., no signal is received at a point on the N2 network), the NCU will issue a command to restore normal communication.
1.2 Operator Station Based on the specific functional requirements of the building, we made a series of improvements to the interface, features, and functions of the METASYS system operator station, adding many more intuitive visual display effects. Furthermore, through OPC (OE for process control) software technology, all equipment management systems can be centrally completed under a simple and clear graphical display. Currently, we refer to the improved operator station system as M5. Its main features are described below:
Multi-screen display: Displaying all the information of a large centralized automation system on a single operator's screen is a major challenge. The M5 operator station solves this problem with its screen management system. This technology can be used to support multi-screen display in large buildings, multi-building complexes, and various networks.
Reusing Existing Graphics: Whether it's graphics from a Johnson Controls workstation or other graphic formats, the Metasys workstation can reuse them. Drawing software such as CorelDraw, Visio, and AutoCAD, along with digital cameras, video capture cards, and digital scanners, provide abundant graphic resources. The workstation's flexibility greatly reduces the workload for programmers and operators.
Animated Interface: The M5 operating system features a brand-new animated interface, complete with music and narration, to vividly describe the situation on-site. It can also transmit real-time images of the controlled equipment in the building to the operator station through the integrated system, thereby providing more accurate and direct guidance to the operator on the actions to take.
Employing dynamic signals with color gradients, Metasys Workstation graphics technology provides complete dynamic graphics control, including display, disappearance, blinking, rotation, animation, and color gradients. All controls are defined through easy-to-use and understandable icon-based dialogs; the function of any icon can be directly associated with another point or arbitrarily defined by building users as needed.
Action Trends: Metasys Workstation provides building users with data analysis curves for energy management and equipment diagnostics. This detailed information helps in better understanding the implementation process of relevant control functions. Building managers can use these curves to analyze the maintenance status of controlled equipment and whether it is operating at its optimal condition.
1.3 Network Controller (NCU)
A network controller (NCU) is a modular, intelligent control panel that forms the heart of the METASYS network. Multiple NCUs can tightly connect the management of every aspect of a building, enabling comprehensive and integrated management. By sharing all information across the network, each NCU can provide optimal control across the entire building using advanced control algorithms.
The network controller has a variety of statistical control functions.
The network controller can be configured with a handheld terminal detector, which can completely replace the function of the operator station, accessing all information in the entire system and issuing control commands.
1.4 Direct Digital Controller (DX-9100)
The direct digital controller is the front-end device of the Metasys system. It is directly connected to the relevant facilities in the building and then connected to the network controller via the N2 bus. Both the network controller and the central operator station can exercise overriding control over it.
Direct digital controllers can support monitoring points of the following different types:
- Analog Input (AI)
Digital Input (DI)
Analog Output (AO)
- Digital Output (DO)
It has a programmable control module and a PC logic operation module. In addition to performing various calculations and PID loop control functions, it also has a variety of statistical control functions and can simultaneously set the time control level.
The controller has the function of independent operation. When the central operating station and network controller have problems, the controller is not affected and continues to operate to complete all the original monitoring functions.
It supports point-to-point communication and can dynamically access data with the METASYS network.
The transmission module (XT) can be connected to the expansion module (XP) to increase the capacity of control input/output points, providing flexible configuration and allowing monitoring of these points via the built-in ED.
The real-time data of the DDC is stored in RAM equipped with a battery.
1.5 Handheld Detector/Network Terminal The handheld detector is used by building maintenance personnel to inspect network controllers and direct digital controllers in the building automation system. Through the detector, maintenance personnel can change setpoints and obtain relevant data, alarms, and status. The inspection process will not interrupt or interfere with the normal operation and communication between the controllers.
Network Terminal (NT) enables building management or maintenance personnel to directly monitor the operation of all devices within the Metasys system. Regardless of which NCU the NT is connected to, all information can be accessed from anywhere in the building using the NT.
The touchscreen input and multi-touch display make it easy to use.
The menu prompts and online help make it easy for users to navigate.
Five levels of password protection ensure network security.
2. METASYS System Monitoring Content The METASYS monitoring system, which centrally monitors buildings, mainly includes:
Refrigeration and air conditioning systems; power supply and lighting systems; water supply and drainage systems; security and patrol systems; fire protection systems.
Elevator and escalator system
Siemens APOGEE Peak System
APOGEE Building Automation System is a new generation building automation/system integration platform launched by Siemens. The complete system consists of four main parts: INSIGHT monitoring software, DDC controller, sensors, and actuators.
A brief explanation of the Siemens APOGEE system is as follows:
1.1 Central Work Station
The central workstation system, consisting of a PC host, a color LCD monitor, and a printer, is the core of the BAS system and can be directly connected to Ethernet. All monitored electromechanical equipment within the building is centrally managed and displayed here. It comes pre-installed with Chinese/English Insight software, providing operators with drop-down menus, human-machine interfaces, and dynamic graphical displays, offering a user-friendly and easy-to-learn interface. Operators do not require specialized software knowledge and can manage the entire control system using only a mouse and keyboard.
1.2 Operating System
The operating system provides a powerful working platform for the building automation system, allowing operators to access and monitor various data within the system through the system program.
1.2.1 Command Input and Menu Selection Methods
In addition to using the regular keyboard, operators can also use the mouse to perform various operations, including starting and stopping, changing setpoints, and selecting menus.
1.2.2 Graphic and Text Display
Operators can display each monitoring point in the building automation system using graphics or text.
1.2.3 Display of Multiple Data: The operating system has the ability to display multiple data in a "window" manner at the same time, so as to facilitate the analysis of different performances and truly achieve real-time and multi-tasking.
1.2.4 Password Protection
Multi-level passwords provide owners and managers with an effective protection tool. They can manage and restrict access to the building automation system from different departments, while preventing unauthorized access and improving system security.
1.2.5 Color dynamic graphics display
To enable alarms to be identified more quickly and system performance to be analyzed more easily, the system provides color dynamic graphic displays, including floor plans and system diagrams of electromechanical devices.
1.2.6 System Architecture and Definition
All temperature and device control strategies and energy-saving programs can be determined by the user, and defining or modifying the programs will not affect the normal operation of the building automation system.
1.3 Insight Software Functions
Insight monitoring software is an integrated management software that provides users with building management and monitoring through a dynamic graphical interface. It can support up to 25 clients running simultaneously.
Insight monitoring software provides users with three main functions for the APOGEE system:
1. Monitoring function: Users can monitor the operating status of the APOGEE system control equipment and the control effect of the controlled object in real time and in history through applications such as dynamic graphics and trend charts.
2. Control Functions: Users can control the start, stop, and adjustment of building automation equipment through application programs such as control commands, program control, and schedule control.
3. Management functions: including user account management, system device management, program upload and download management. Users can also understand the status of the APOGEE system itself through system activity records, reports and other applications.
By installing optional components, functions such as remote automatic dialing service, emulation terminal, support for web services, support for remote notification, and support for virtual controllers can also be achieved.
1.4 Direct Digital Control (DDC)
A DDC is a controller used to monitor and control electromechanical equipment in a system. It is a complete controller that includes both hardware and software, and can operate independently without being affected by network or other controller failures.
The controller primarily consists of a 32-bit or 16-bit microprocessor and point terminal modules of various types, enabling it to operate independently of the central control host or networked. Furthermore, in the event of a power outage, the DDC's backup battery ensures that data in the RAM is not lost for 60 days. In short, the DDC has the following functions:
1) Use Powerful Process Control Language (PPC) to write the program.
(2) Advanced proportional-integral-derivative HVAC control, closed-loop regulation algorithm can minimize oscillation and maintain precise control.
(3) Comprehensive alarm management, historical data recording and operator control and monitoring functions.
(4) Provides a built-in energy management program SSTO for energy management.
1.5 The APOGEE system is mainly used for centralized monitoring of buildings, including:
Air conditioning units, fresh air handling units, power distribution system
Lighting system; Water supply and drainage system; Cold and heat source system; Standby generator system
elevator system
Variable air volume system
HBS Building Automation System of Beijing Lida Hengxin Technology Development Co., Ltd.
1. System Overview: The HBS Building Automation System is a building automation system fully compliant with the BACnet international standard. It is responsible for monitoring and managing the building's HVAC, water supply and drainage, power distribution, lighting, elevators, and other systems, ensuring a comfortable and safe building environment while achieving high energy efficiency. The HBS building automation system can be flexibly configured to meet different user needs, suitable for both small single buildings and large building complexes with complex functions and numerous devices. It can be widely used in various types of buildings, including industrial and mining enterprises, commercial centers, office buildings, exhibition centers, stadiums, hospitals, schools, and residential communities.
2. System Features:
Standardized Communication Protocol: The HBS building automation system adopts the internationally standardized protocol—BACnet. BACnet is the only international standard in the building automation industry, possessing strong versatility. It allows for the integration of equipment from different manufacturers into a single system and enables convenient future expansion and upgrades.
Digital Energy Management: The system's precise energy management function not only allows users to have a clear understanding of the details of every expense related to water, electricity, gas, and cooling (heating) loads, making their consumption transparent, but also provides energy-saving control solutions, realizing the digitalization and precision of energy management.
Integrated Functional Design: The integrated functional design enables interconnection and information sharing with security, fire protection, communication, and office systems. Simplified Communication Structure: Utilizing a single-level network (Ethernet) as the communication platform, each field controller is directly connected to the Ethernet, eliminating the need for dedicated network communication equipment.
Intelligent operation: The user interface is entirely in Chinese, presented in a virtual reality format, with animated operation, making it easy to learn and use, and simple to operate.
Decentralized control and regulation: It adopts a truly distributed control mode without central control, which is decentralized to local control. The control and regulation functions can be completed independently by the system's controller without relying on the host.
Modular system composition: This system allows for easy installation of workstations or controllers in any segment of the Ethernet network without additional costs. The system can be easily expanded from dozens to tens of thousands of points without changing the cabling.
Remote equipment maintenance: System software faults can be diagnosed and maintained remotely, reducing maintenance time and improving efficiency.
In summary, every detail of the HBS building automation system, from design to application, embodies the concepts of health, energy saving, comfort, and convenience.
3. Network structure:
The HBS system is based on the high-performance architecture of BACnet/IP Ethernet, allowing users to make full use of existing network devices and resources. Whether organizing a large network or a small standalone system, it can be done easily and efficiently.
Edited by: He Shiping
