SCADA system, ie data acquisition and monitoring control system. The SCADA system is an industrial computer-based DCS and power automation monitoring system; it has a wide application field and can be applied to many fields such as data collection, monitoring control, and process control in the fields of electric power, metallurgy, petroleum, chemical engineering, gas, and railways.
In the power system, the SCADA system is the most widely used and the technology is most mature. It occupies an important position in the telecontrol system and can monitor and control the on-site operating equipment to achieve various functions such as data acquisition, equipment control, measurement, parameter adjustment, and various types of signal alarms. Remote "functions. RTU (Remote Terminal Unit), FTU (Feder Terminal Unit) is an important part of it. It has played a very important role in today's integrated automation of substations.
instructions
The SCADA system is an industrial computer-based production process control and dispatch automation system. It can monitor and control on-site operating equipment.
Due to the different requirements for SCADA in various application areas, the development of SCADA systems in different application areas is not entirely the same.
The SCADA system is the most widely used in power systems, and the technology is also the most mature. As the most important subsystem of the energy management system (EMS system), it has the advantages of complete information, improved efficiency, correct understanding of system operation status, quicker decision-making, and can help quickly diagnose system failure status. It has become an indispensable power dispatch. Missing tools. It plays an irreplaceable role in improving the reliability, safety and economic efficiency of power grid operation, reducing dispatchers, realizing automation and modernization of power dispatch, and improving the efficiency and level of dispatch.
The application of SCADA to railroad electrification telecontrol system is earlier. It plays a very important role in ensuring the safe and reliable power supply of electrified railways and improving the dispatch and management level of railway transportation. In the course of the development of the railway electrification SCADA system, with the continuous development of industrial computer technology, there are different products in different periods. At the same time, China has also introduced a large number of SCADA products and equipment from abroad. These have driven the railway electrification telecontrol system Higher goal development.
Architecture Hardware
Usually the SCADA system is divided into two levels, the client/server architecture. The server communicates with hardware devices for data processing and computing. In general, the touch function of an industrial tablet computer is used for human-computer interaction, such as displaying texts and animations on the scene, and operating on-site switches and valves. There is also an “ultra-long-range customer” that can be monitored over the Internet via the Web-based wired or wireless communication capabilities. Hardware devices (such as PLCs or industrial tablets) can generally be connected either point-to-point or bus-to-server. The point-to-point connection is generally through the serial port (RS232), and the bus mode can be RS485, Ethernet and other connection methods.
software
SCADA consists of many tasks, each of which fulfills a specific function. Servers located on one or more machines are responsible for data acquisition, data processing (eg, range conversion, filtering, alarm checking, calculations, event logging, history storage, executing user scripts, etc.). Servers can communicate with each other. Some systems further divide the server into separate dedicated servers, such as alarm servers, logging servers, history servers, login servers, and so on. Each server logically serves as a unified entity, but it may physically be placed on different machines. The advantage of classification is that it can manage all kinds of data of multiple servers and divide the work together. The disadvantage is that it is inefficient and local failures may affect the entire system.
Communications
Based on industrial computers or industrial servers, communication in SCADA systems is divided into internal communication, communication with I/O devices, and external communication. There are generally three forms of communication between client and server and between server and server: request, subscription, and broadcast. The communication between device drivers and I/O devices is generally on-demand. Most devices support this type of communication. Of course, some devices support active sending. SCADA communicates with the outside world in many ways. Such as OPC, generally provide OPC client, used to communicate with the OPC server provided by the equipment manufacturer. Because OPC has Microsoft's own standard, the OPC client can communicate with the various OPC servers provided without modification.