1、 外文资料翻译 1 PLC controller can be programmed (Programmable logic Controller, refers to computer technology-based new industrial control devices. In 1987, the International Electrotechnical Commission (International Electrical Committee) issued a draft standard for PLC made the following definition of
2、PLC : PLC name in English Programmable Logic Controller, the Chinese called the programmable logic controller, the definition is: a digital computing operation of electronic systems, in industrial environments for applications. It uses a class of programmable memory, for its internal storage procedu
3、res, the implementation of logic operations, sequence control, timing, counting and arithmetic operations, such as user-oriented instruction, and digital or analog input / output control of all types the machinery or the production process. PLC is programmable logic circuits, and hardware is also a
4、very strong combination of language, in the semiconductor has a very important application, is a place where there semiconductor PLC ， PLC is a specialized in industrial environments for applications designed to operate electronic digital computing device. It uses the memory can be programmed to sto
5、re in its internal implementation logic operations, the order of operations, timing, counting and arithmetic operations, such as operating instructions, and can be digital or analog input and output, control of various types of machinery or production processes. PLC and its associated peripheral equ
6、ipment should be in accordance with the industrial control system is easy to form a whole, easy to extend its functionality the principle of design. 2 Characteristics of the PLC 2.1 high reliability, strong anti-interference ability 2.2 supporting complete, fully functional applicability 2.3 easy to
7、 learn and use by engineering staff welcomes the 2.4 System design, construction work in small, easy maintenance, easy to transform 2.5 small size, light weight, low energy consumption 3 PLC Basics PLC course of development in the industrial production process, a large number of switches to control
8、the volume of the order, which in accordance with the terms of the order of the logic of action, and in accordance with the logic of the relationship between the chain to protect the control action, and a large number of discrete volume data collection. Traditionally, these functions through pneumat
9、ic or electrical control system to achieve. 4 PLC applications At present, PLC at home and abroad, has been widely used in iron and steel, petroleum, chemical, electric power, building materials, machinery manufacturing, automobile, textile, transportation, environmental protection and cultural ente
10、rtainment and other industries, the use can be broadly divided into the following categories. (1) The logic control switch PLC which is the most fundamental and wide-ranging applications, which relay to replace the traditional circuits, the realization of the logic of control, order control, equipme
11、nt can be used for a single control group can also be used for multi-line control and automation. Such as injection molding machines, printing presses, Protocol machinery, modular machine tools, grinding machines, packaging production line, assembly line, such as electroplating. (2) Analog control I
12、n the industrial production process, there are many changes in the amount of continuous, such as temperature, pressure, flow, level and speed are all analog. In order to deal with analog programmable controller, the need for analog (Analog) and Digital (Digital) between the A / D conversion and D /
13、A conversion. PLC manufacturers are supporting the production of the A / D and D / A converter module, so that the programmable controller used to simulate the volume control. (3) Motion Control PLC can be used in a circular motion or linear motion control. From the control configuration, the early
14、switch directly to I / O modules to connect the location of sensors and the executing agency, is now generally use a dedicated motion control module. Such as stepper motor or servo-driven single-axis or multi-axis motor control module location. PLC worlds major manufacturers of products that almost
15、every motion control functions, a wide variety of machinery, machine tools, robots, elevators and so on. (4) Process Control Process control refers to the temperature, pressure, flow volume of the closed-loop control simulation. For industrial control computer, PLC to the preparation of a wide range
16、 of process control algorithm to complete the closed-loop control. PID regulation of a general closed-loop control system with a lot of adjustment methods. PLC have a large and medium-sized PID modules, many small PLC module also has this feature. PID operation processing is PID-specific subroutines
17、. Process control in metallurgy, chemical industry, heat treatment, boilers, control and so on have a very wide range of applications. (5) Data Processing PLC with modern mathematics (including matrix operations, function operations, logic operations), data transfer, data conversion, sorting, look-u
18、p table, bit operation functions, you can complete the data collection, analysis and processing. These data can be stored in the memory of the reference value of comparison, the complete control of certain operations, can also be used to send communication to other intelligent devices, or to print t
19、hem tabulation. Generally used in large-scale data processing control systems, no control, such as flexible manufacturing systems； also can be used for process control systems, such as paper making, metallurgy, food industry in a number of large-scale control system. 5. PLC situation at home and abr
20、oad In the course of industrial production, a large number of switches to control the volume of the order, which in accordance with the terms of the order of the logic of action, and in accordance with the logic of the relationship between the chain to protect the control action, and a large number
21、of discrete volume data collection. Traditionally, these functions through pneumatic or electrical control system to achieve.Chinas introduction of programmable controllers, application, development, production is accompanied by the beginning of reform and opening up. The first device in the introdu
22、ction of large-scale use of the programmable controller.Then in a variety of production equipment and products, expanding the application of the PLC. At present, our country has its own small and medium-sized programmable controller can be produced. Electric Co., Ltd. Shanghai East house CF producti
23、on line, Hangzhou Machine Tool & Electric Appliance Factory production DKK and D series, the production of Dalian Modular Machine Tool Research Institute of the S series, the Suzhou factory computer YZ series produced a wide range of products has a certain scale and in industrial products access to
24、the application. In addition, Wuxi Huaguang companies, rural island of Shanghai Sino-foreign joint venture companies in China is relatively well-known manufacturer of the PLC. It can be anticipated that with the deepening of Chinas modernization process, PLC in China will have a broader application
25、of heaven and earth. 6. PLC Future In the future, PLC will have greater development. From a technical point of view, the new achievements in computer technology will be more programmable controller used in the design and manufacturing, there will be faster, bigger storage capacity, intelligent speci
26、es emerged stronger； from the product scale of view, further to the direction of ultra-small and large development； from the matching of products, the variety of products will be more rich, more complete specifications, the perfect man-machine interface, a comprehensive communications equipment will
27、 be better adapted to a variety of industrial control the demand for places； from the market point of view, the production of more varieties of their respective products as international competition and to break, there will be a few brand monopoly situation in the international market, there will be
28、 international programming language； from the development of the network, the programmable controllers and other industrial control computer network constitutes a large-scale programmable logic controller control system is the development direction of technology. At present, computer distributed con
29、trol system DCS (Distributed Control System) has been a large number of programmable controller applications. Along with the development of computer networks, programmable controllers, as automation and control networks and international networks, an important part in industry and industrial fields other than play an increasing role
