1Programmable Controller Theory and Its Application可编程控制器及应用(双语)2main contents of the course课程内容本课程以西门子S7-300/400大中型可编程控制器（PLC）为背景机型，重点介绍可编程控制器(Programmable Controller)的工作原理（theory）、系统硬件（hardware）、指令系统（Instruction Set）、编程软件（Programming Software）、设计(Design)方法等。3About this coursel共36学时，课堂讲授30学时，实验6学时 l课程成绩=期末试卷成绩(60%)+实验成绩 (20%)+平时作业成绩(20%) l期末试卷：编程题，基本操作规范、基本 概念 l实验成绩：考核3-5个操作（认真做实验） l平时作业成绩：内容是否符合要求，格式 是否规范41. L.A. Bryan，L.A. Bryan.Programmable Controllers Theory and Implementation.2nd edition. An Industrial Text Company Publication ，Atlanta Georgia USA2. 李希胜 舒雄鹰 编，校内讲义 Programmable Controller Theory and Its Application 3. 李希胜 孙昌国 舒雄鹰 编著，中国计量出版社可编程控制器原理及应用 4. 廖常初 主编 机械工业出版社S7-300/400 PLC应用技术5. 网站：西门子（中国）自动化与驱动集团 下载中心http:/www.ad.siemens.com.cn/download/ 6. 西门子 S7300中文手册，英文手册 Reference参考书目51.1 Definition1.2 Control system overview1.3 The benefit of programmable control1.4 Fundamental structure of PLC1.5 PLC Product Application Ranges1.6Ladder Diagrams And The PLC1 Introduction61.1 DefinitionWhat is a programmable controller?Programmable controllers, also called programmable logic controllers or PLCs, are solid-state members of the computer family, using integrated circuits instead of electromechanical devices to implement control functions. They are capable of storing instructions, such as sequencing, timing, counting, arithmetic, data manipulation, and communication, to control industrial machines and processes. 7|a microprocessor-based industrial controller, the functions of which are determined by a stored program.81-2 A Historical Backgroundl In 1968 GM Hydramatic (the automatic transmission division of General Motors) issued a request for proposal for an electronic replacement for hard-wired relay systems. l Their primary goal was to eliminate the high costs associated with inflexible, relay-controlled systems. Some of the initial specifications included the following: The new control system had to be price competitive with the use of relay systems. The system had to be capable of sustaining an industrial environment.9 The input and output interfaces had to be easily replaceable. The controller had to be designed in modular form, so that subassemblies could be removed easily for replacement or repair. The control system needed the capability to pass data collection to a central system. The system had to be reusable. The method used to program the controller had to be simple, so that it could be easily understood by plant personnel.10十项技术指标编程简单可靠，可在现场修改程序 硬件维护方便，最好是插件结构 可靠性要明显高于继电器控制系统 体积要明显小于继电器控制柜 价格便宜，其性价比要高于继电器控制系统 输入可以是AC 115 V 输出为AC 115 V ，2 A 以上，能直接驱动电磁阀具有数据通信功能 扩展时，原有系统只需做很少改动 用户程序存储器容量至少可扩展至4 kB11l by 1969, the programmable controller had its first product offsprings. The winning proposal came from Bedford Associates of Bedford, Massachusetts. The first PLC, designated the 084 because it was Bedford Associates eighty-fourth project, was the result. Bedford Associates started a new company dedicated to developing, manufacturing, selling, and servicing this new product: Modicon, which stood for MOdular DIgital CONtroller. One of the people who worked on that project was Dick Morley, who is considered to be the “father“ of the PLC.12继电器控制系统先进自动控制系统13What is a program? a set of instruction telling the controller how to behave. stored in the controllers memory. How does a programmable controller differ from a computer?TaskProgrammerEnvironmentPLCControl and RegulationElectrical EngineerIndustrial environment ComputerCalculation and DisplaySpecialistOffice, domestic application14Why are programmable controllers so common?Cost effectiveHave significant advantages over traditional control systems based on relays or pneumatics.Where are they used?Every industry where automation is involved, from individual machines to whole processes.In commercial, institutional and industrial premises.Domestic application. (cheap and compact)15What are the main advantages?Flexible, reliable, compact and cost effective.Are all programmable controller the same?Broadly similar in a functional sense. (功能)Differ in size, programming detail and mechanical design. 尺寸、编程、机械设计等Most manufacturers offer several models with different levels of performance. 以适应不同任务需要。(cater for提供，迎合)16What tasks does a programmable controller perform?The control tasks previously undertaken with electrical and/or controls, e.g. interlocking, sequencing, timing and counting.Calculation, communication and monitoring tasks far outside the competence of traditional systems.Does a programmable controller eliminate contactors （接触器） and valves（阀门）?No. 171.2 Control system overviewThree characteristic features of a control system: l Certain actions to be taken l Certain rules governing those actions l The rules take account of certain relevant conditions in the plant. Example. Traditional control system (the wiring makes rules!)and programmable control system (program).18