SCADA System Overview

　　SCADA system is supervisory control and data acquisition. It is a computer-based production process control and scheduling automation system. The functions of monitoring, measuring and controlling various equipment parameters on site can be realized.

　　1、 Development history of SCADA system:

1. The first generation system based on special computer and special operating system. 2. Due to the popularity of computers, the second generation system based on general-purpose computers and general-purpose operating systems was developed in the 1980s, mainly based on minicomputers and UNIX operating systems. 3. In the 1990s, the third generation system was developed based on computer network technology and relational database technology, mainly based on SQL database system and TCP / IP network technology. 4. Due to the development of Internet technology, object-oriented technology, Java technology and other technologies, SCADA system can conduct data acquisition, exchange and equipment control based on Internet, so as to form the current fourth generation system. The fourth generation system is constantly developing and improving.

2. 
   

　　2、 Components of SCADA system:

　　Generally speaking, any system with system monitoring function and data acquisition function can be called SCADA system. Generally speaking, the system includes two parts: hardware system and software system.

　　Hardware system generally includes data acquisition equipment, control equipment and data communication equipment. SCADA system is generally realized through digital quantity or analog quantity. Its typical acquisition and control equipment includes switching value input and output module, analog quantity acquisition and control module and other equipment. Data communication equipment is generally determined based on data communication mode, Communication modes include wireless data transmission, fieldbus transmission, TCP / IP network transmission, optical fiber transmission and satellite communication. The computer is placed in the monitoring center to analyze and sort out the data transmitted by the system, and issue commands to control the system.

　　The data acquisition, monitoring and control software system has the following characteristics:

　　1. Graphical interface, so that people can intuitively monitor the whole system and conveniently watch the collected data.

　　2. Dynamic simulation of system status. The monitoring and control system generally transmits the data to the monitoring center in real time. The dynamic simulation can be used to intuitively monitor the system.

　　3. Real time data and historical trend. SCADA system can play a real role only when the real-time data are completely recorded and the relevant data are calculated by using relevant calculation methods on this basis.

　　4. Alarm processing system: in case of abnormal conditions in the system, the system can send alarm information and deal with relevant problems in time.

　　5. Data acquisition and recording: the system collects the data distributed in various places to the monitoring center through relevant data acquisition equipment, and records it for use by the system.

　　6. Data analysis: if a system only records the data collection of each collection point, its function is incomplete. Only by analyzing the data and drawing relevant conclusions through the analysis can it really play a role for people's reference. 7. Report output: after analyzing the data collected by the system, draw relevant conclusions and form report output.

　　The software and hardware of data acquisition, monitoring and control system are generally connected in three ways: 1 Standard communication protocol. 2. Standard data exchange interface. 3. Specially customized binding driver.

　　3、 Application fields of SCADA system:

　　1. Power dispatching monitoring mainly plays the role of real-time mastering the operation state of the system and quickly diagnosing the fault state.

　　2. Water plant monitoring, water supply scheduling, real-time collection of water flow, billing and other control, find leakage maintenance points, and avoid the waste of water resources.

　　3. The monitoring, alarm and measurement of natural gas has changed the traditional monitoring mode of manual recording, improved the speed of production scheduling, and can timely find and deal with natural gas leakage and other accidents as soon as possible.

　　4. Oil field pipeline system mainly plays the role of automatic control of industrial site or remote, comprehensive and real-time monitoring of process flow, and ensuring the complete unity of production, scheduling and management;

　　5. Expressway automatic monitoring can transmit traffic condition and accident information to the monitoring center.

　　6. Railway electrification mainly refers to real-time monitoring of train operation and real-time alarm of fault points. Ensure the normal operation of the train.