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外文资料In the high-end market, PLC and industrial PC something together, because the industrial PC in the data integration and communication capabilities to the user a lot of temptation. PC also introduced Ethernet TCP / IP network and interconnection with the concept of the Internet. But now, PLC manufacturers can claim, If you want this, we can do. European leader in the PLC, Siemens A & D and Schneider Electric, provides a powerful high-end controller family, regardless of PLC or industrial PC, and at the same time promoting the field of PLC and industrial PC development. The recent announcement by Siemens S7-400 PLC series of significant performance increase, the CPU performance of the previous 3 times the communications capacity is 2 times the previous. Siemens is still the most high-end of the S7-400 series, an increase of another innovation： communications processor with integrated 4-port Ethernet switch. The need for external switch, the Ethernet can be used for small-scale model of the economy. However, the communications processor real difference is that from now on it is a higher stage of development to middle-class, at a higher stage, Siemens will use high-end PLC and integrated Profinet V3 switch external devices, can provide real-time control. Schneider Electric has developed a substantial high-end CPUs performance, the introduction of the new Unity software programming, XML data format. In the embedded web server and multi-port communication, the new functions of the CPU more and more like PC. Integrated design of the platform Mitsubishi Electric PLC will be the further development of 2-3 years, and now the horizon： multi-processor and system platform. From the users point of view means that function blocks can be placed on a plate, PLC and network of experts believe that Hugh Tasker, These can include standard PLC technology, but a mix of motion control and process control, or full-featured PC performance, the use of SCADA or local program Soft HMI technology. The development of what is it? In his view, the users, the biggest benefit is the simplified control system. Do not have to integrate a lot of PLC, they are connected, and then operation and maintenance, and now many of the system will reduce the number of PLC, and even the introduction of a. This can greatly save time for installation and maintenance, the durability of the whole system is also more . He also speculated the future, in a very long period of time, Bluetooth technology and wireless Ethernet technology will be more extensive. It will first start in a small area, but in terms of reliability, durability and easy acceptance will be improved, manufacturers will be likely to seek the application of wireless technology may one day even the most basic cable they have not been saved. B & R Automation is a supplier of control products, the provision of industrial PC, but compared to other PLC manufacturers, which in the field of PLC is also quite a long time. But they never dwell on the PC and the PLC Which Which weak strong together in the common development. B & R and now see the development of some opportunity, perhaps both to the continuous integration of technology. In the past few years, the classic development of programmable logic controller has always been to the embedded PC technology development, B & R Business Manager Anton Meindl think, PC technology has its advantages - the enormous computing power, and the Internet The combination of technology, fast Ethernet and USB interface, can combine the traditional advantages of the PLC system, such as practical, durable and strong, and modularity. Omrons PLC + Inverter Omron introduced its first AC inverter 3G3MV, can be used for motion control product lines. Applicable to small-scale motor control (0.1 to 7.5 kW). It allows users to choose non-sensor vector control can provide high torque at low speed in the output frequency of 1 Hz was also able to guarantee 150 percent of torque. Also has the I / O and communication functions. However, in November last year, it increased by another function, it can be some unusual, an increase of Omron PLC Plug & Play modules used, and not just an annex, is a complete PLC, equivalent to the standard Omron CPM2C -S PLC. The use of dual-port RAM, PLC and inverter direct the I / O, data and associated parameters. PLC has its own I / O, can provide data directly to the inverter： input encoding, interrupt output, as well as digital, and PWM output pulse. Omron believes that this combination of products for the network or provide an ideal control program, to meet the location and sequence context in the precise control requirements, but also for manufacturing of multi-step production lines and intelligent packaging conveyor lines. Omron PLC + The combination of inverter, if the order for the pump controller, in the composition of the three pump hydraulic control system. PLC + converter combination of the first pump of the closed-loop continuous control, the other two pipes connected in parallel to the pump on / off control. Man-machine interface (MMI) can monitor SMS wireless signal can be sent to maintenance personnel. PAC in the United States In the United States, market strategy and sometimes even more than the technology itself attention in 2003, the industry there is a new popular vocabulary： Programmable Automation Controllers (Programmable Automation Controller, PAC). Terms of the new ARC Advisory Group from the market research company Craig Resnick, he thought, PLC is very active and well-developed, with a strong vitality. However, PLC an effective tool for this industry is changing many aspects, and continuously increase its charm. automation suppliers are committed to the development of PLC in order to meet market and special user needs. functional enhancements to a new series of the surface of the system. PAC based on open industry standards, features a multi-field, General open platforms and high performance. ARC coin the term, in order to help user-defined applications to help manufacturers when talking about their products more clearly. Whether manufacturers will be the product name changed from the PLC to PAC, remains to be seen. However, GE Fanuc has not the slightest hesitation, they immediately accepted the concept of PAC, but also show in Hanover publicly announced that its new flagship product known as the PACSystems. GE Fanuc name used to express a combination of its traditional PLC products and the advantages of PC hardware with a common programming environment, Cimplicity Machine Edition software. There is a separate software-controlled engine, a development tool, multi-goal programming hardware. Hardware includes not only the two new PACSystems processor, including GE Fanuc Automation to other products, such as Tablet PC, Embedded PC, MHI and its new motion control system of the S2K. PACSystems control on behalf of industry innovation, which enables centralized control, rather than have nothing to do all the parts together, GE Fanuc Automation (Europe) John Pritchard. Believe that the one engine, with a development tool, the user can make use of powerful engineering environment for multiple applications. PAC you have I have November 2003 Rockwell announced that its technology for the PAC leader, and its products ControlLogix and CompactLogix PLC fact that PAC. We have seen the user data control system of unlimited enthusiasm, the user can collect security, finance, quality assurance procedures, and other information, that Ken Deken, Rockwell Automation, to meet the requirements of users, users need to control the between business systems and the direct contact information at all times. He believes that, with the constant development, PAC will be a lot of ways to deal with data and with scalability in multi-project control, integrated business systems analysis and life cycle cost management can march forwardProgrammable logic controller (PLC) technology has made remarkable achievements and become a subject of rapid development and innovation in the field of automation. With the increasing maturity of technology, PLC has gradually developed into an industrial control device with microprocessor technology as the core, integrating computer technology, automation control technology and communication technology. With the cooperation of network technology and configuration software, the application of PLC is like a tiger with wings.Programmable logic controller (PLC) is widely used in the industrial field, which is not only a substitute for relay logic circuit, but also a component of field control and the core part of control equipment. With the improvement of automation, it can be used not only as a part of field control, but also as a control part of field higher-level management. With the development of network technology, as a mature technology, PLC has been widely used in machinery, metallurgy, chemical, petrochemical, cement, food and beverage, pharmaceutical and other fields, greatly improve labor productivity and automation.Mitsubishi, Siemens is Chinas leading industrial solution provider in a number of business areas, providing innovative, reliable, efficient, and quality products in manufacturing automation, process industrial automation, motion control, drive, low voltage control, and electrical installation technologies. And to provide a comprehensive system of solutions and services. Products cover a wide range of information and communications, automation control, power, transportation, medical, lighting and other industries in the leading edge.Mitsubishi, Siemens control technology, can continue to integrate new technologies, new methods, innovation. Among them, Siemens control technology further makes new breakthroughs in e-manufacturing and e-control technology, and new products keep emerging, providing very reliable control and application for a variety of automation control equipment.History of PLCIn the 1960s, the automatic control system of automobile production line was basically composed of relays. Each modification of the car at that time led directly to the redesign and installation of relay controls. With the development of production, the cycle of vehicle model update is getting shorter and shorter, so the relay control device needs to be redesigned and installed frequently, which is very time-consuming, laborious and costly, and even hinders the shortening of the update cycle. In order to change this situation, general motors in the United States in 1969 public bidding, the requirements of the new control device to replace the relay control device, and put forward ten bidding indicators, the requirements of easy programming, field modification procedures, easy maintenance, the use of modular structure. In 1969, American digital company developed the first PLC, which was successfully used on the automatic assembly line of American general motors.This new type of industrial control device with its simple and easy to understand, easy to operate, high reliability, general flexibility, small size, long service life and a series of advantages, soon in the United States other industrial applications, and soon successfully applied to food, beverage and other industrial fields. The emergence of this new industrial control device is also highly valued by other countries. In 1971, Japan introduced this new technology from the United States and soon developed Japans first PLC. 1973 western European countries also developed the first PLC. China began to develop from 1974, in 1977 began to enter the industrial application.Since 1980 s, with large scale and very large scale integrated circuit, such as the rapid development of microelectronics technology, and a handful of 32-bit microprocessor with a 16 bit of PLC has been amazing development, makes the PLC in design, performance, price and application has the new breakthrough, not only enhanced control function, power consumption and reduced volume, cost reduction, increased reliability, programming is more flexible and convenient, and the fault detection and remote I/O and communication network, data processing and the development of image display, also include a convenient debugging and testing tools, simulation tools, etc., PLC has been widely used to control complex continuous production processes. At present, PLC has become one of the three pillars of factory automation.In February 1987, the international electrotechnical commission (IEC) defined a programmable controller as follows: a programmable controller is an electronic system for digital operations, designed for use in industrial environments. It USES a class of programmable repositories to internally store programs that perform customer-facing instructions such as logical operations, sequence control, timing, counting, and arithmetic operations, and control various types of machinery or production processes through digital or analog input/output. The programmable controller and its related peripheral equipment are designed according to the principle that the system is easy to form a whole and easy to expand the function.PLC is so widely used, and its superior performance is inseparable. Main features of PLC:1. High reliability, strong anti-interference abilityIn the traditional relay control system, a large number of intermediate relays are used, and the reliability of the system is greatly reduced due to the aging and falling off of the components, the vibration of electric shock and bad contact. In the PLC control system, a large number of switch action is completed by non-contact semiconductor circuit, due to poor contact and other reasons caused by the fault greatly reduced.In addition, PLC in the hardware and software also took the following strong measures to improve its reliability.In terms of hardware, photoelectric isolation is adopted for all I/O interface circuits, so that the external circuit in the industrial site is electrically isolated from the internal circuit of PLC. Each module adopts photoelectric shielding measures to prevent radiation interference. The switching power supply with excellent performance and various forms of filtering are used for the power supply system and the input circuits to eliminate or suppress the high-frequency interference. Select the selected device strictly; Adopt the module structure more, once a module has a fault, can quickly replace the module, so as to shorten the system downtime as possible.In terms of software, PLC has a good self-diagnosis ability, once the power supply or other software, hardware abnormal situation, CPU immediately take effective measures to prevent the expansion of the fault; PLC set a monitoring timer, if the program cycle execution time exceeded the specified value, it indicates that the program has entered a dead cycle, can immediately alarm.For large PLC systems, it is also possible to adopt a redundant system composed of two cpus or a voting system composed of three cpus to improve the reliability of the system.2. Rich I/0 interface modulesPLC for different industrial field signals, such as: ac or dc, switching or analog, voltage or current, pulse or potential, strong or weak electrical signals, can choose the corresponding I/O module to match. For industrial field devices or equipment, such as buttons, trip switches, proximity switches, sensors and transmitters, solenoid coils, control valves and other equipment can choose the corresponding I/O module to connect with it.In addition, in order to improve the PLC operation performance, it has a variety of man-machine dialogue interface module; In order to form industrial control network, also equipped with a variety of communication network interface modules.3. Adopt modular structureIn order to adapt to a variety of industrial control needs, in addition to the unit type of small PLC, the vast majority of PLC are modular structure. All parts of PLC, including CPU, power supply, I/0, etc., adopt modular design. Each module is connected by rack and cable.4. Programming is simple and easy to learn, system design, short debugging cyclePLC programming is mostly similar to relay control lines in the form of ladder diagram, for users, do not need to have computer expertise, so it is easy to be the general engineering and technical personnel to understand and master. In addition, because PLC is through the program to achieve the control of the system, so the designer can design and modify the program in the laboratory, but also in the laboratory to facilitate the system simulation and operation debugging, so that the workload of the site is greatly reduced.5. Simple installation and easy maintenancePLC does not need special machine room, can run directly in a variety of industrial environments. When in use, only connect all kinds of equipment in the field with the corresponding I/O terminal of PLC, and it can be put into operation.PLC failure rate is very low, and has a perfect self - diagnosis and display function. When the PLC or external input device and actuator failure, according to the PLC module on the operation and failure indication device or programming software to provide information, easily find out the cause of the failure. Due to the modular structure, once a failure occurs, the user can replace the module, so that the system can quickly resume operation.In short, a programmable controller is a computer designed and manufactured for industrial applications. Has the rich input/output interface, and has the strong driving ability. But programmable controller products are not for a specific industrial application, in the actual application, its hardware needs to be selected according to the actual needs of configuration, its software needs to be designed according to the control requirements of programming.How PLC works1. Scanning modePLC has two basic working modes, namely RUN mode and STOP mode. In operation mode, the PLC realizes the control function by repeatedly executing the user program. In order to make the PLC output in time to sound, should be at any time possible to change the input signal, the user program is not only executed once, but continue to repeat the execution, until the PLC STOP or switch to STOP mode.2. Scan cycleWhen the PLC is in Run mode, the time required to perform a scan operation is called the scan cycle, and its typical value is about 1100ms. The length of the scan cycle depends on the length of the user program, the type of instructions, and the speed at which the CPU executes the instructions. When the user program is long, the instruction execution time takes up a large proportion in the scanning cycle. Some programs or programmers can provide the current value of the scan cycle, while others can provide the maximum and minimum values of the scan cycle.3. Time after input/outputThe time after input/output is also called system response time, which refers to the time interval between the time when the external input signal of PLC changes and the time when the external output signal changes under its control.The RC filter circuit of the input module is used to filter the interference noise introduced by the input end and eliminate the bad influence caused by the jitter caused by the external input contact. The time constant of the filter circuit determines the length of the input filter time, and its typical value is about 10ms. The lag time of the output module depends on the type of module. The lag time due to the way the scan works may be up to two or three scanning cycles.The total response delay time of PLC is usually only a few tens of milliseconds, which is irrelevant to the general system. The system that the lag time between the requirement input and output signal is as short as possible, can choose the PLC that the scan speed is fast or take other measure.The main application of PLCPLC applications include: special machine tools, textile machinery, packaging machinery, general mechanical engineering applications, control systems, machine tools, building automation, electrical manufacturing industry and other related industries.In short, PLC wide application, powerful function, easy to use, has become one of the main pillars of modern industrial automation, in all fields of industrial production has been widely used.Two typical programmable controllers1. Siemens PLC: Siemens PLC has powerful function, stable system, good performance and quality, and the highest market share. I feel mainly based on Siemens structured programmable way, open good, support a variety of communication protocols. In addition, Siemens applies a variety of man-machine interface and monitoring configuration software to facilitate the communication and integration of equipment from multiple manufacturers. Siemens has made a lot of function blocks to reduce the burden on designers. Omron features less, is suitable for small systems, programming is convenient, the price is slightly lower, but not as stable as Siemens.2. Mitsubishi PLC, Siemens PLC and mitsubishi PLC are mainly into different ideas, mitsubishi Japanese brand, programming straightforward, study up more easily, and Siemens, a German brand, instructions are abstract, learning is difficult, but the order is less, and mitsubishis instruction is more, so the cycle of learning mitsubishi and Siemens are the same; Mitsubishis advantage lies in discrete control and motion control, mitsubishis instruction is rich, has a special positioning instruction, control servo and step easy to implement, in order to realize the action of some complex control and mitsubishis strengths, and Siemens in the weaker, there is no special instructions, do servo or stepper positioning control is not cannot achieve, but the process is complex, control accuracy is not high. Process control and communication control are the strengths of Siemens, whose analog module is cheap and simple, while mitsubishi is weak in this area. Therefore, in view of different control methods of different equipment, we should reasonably choose PLC, with its advantages, avoid its disadvantages. For example, some equipment is just some action control, such as manipulator, can choose mitsubishi PLC, some equipment has servo or step to want to carry out positioning control, also choose mitsubishi PLC; Such as central air conditioning, sewage treatment, temperature control and so on, there are a lot of analog quantity to deal with, you should choose Siemens PLC is more appropriate, a device site has a lot of data to be collected by communication, choose Siemens good control. Learn to choose a certain brand, to combine with the actual situation, see whether to be targeted at various industries, small enterprises, Japanese enterprises, taiwan-funded enterprises mitsubishi more extensive; Large enterprises and the north are used by Siemens more.The development direction of programmable logic controllerLooking forward to the future, PLC will have greater development. Specifically reflected in the following aspects:1. PLC technology will transfer the development of open communication network technology to open control system and integrate PLC into more open industrial control industry. A large number of PLC control devices are now installed in the industrial field, and industrial control software companies have been joined to develop their own industrial pc-based engineering control software. The control software provides virtually unlimited logical control steps for a trapezoid diagram while allowing for data tables of more than a million words; Many 0I/SCADA application interfaces; Built-in Java engine and FTP server for remote maintenance and management; Support users to write their own C, C+, Java programs and device drivers; Suitable for embedded Web service appliance; Online operation mode of program design; Rugged I/0 module support capability and many other standard PLC features; Can run the input or converted a-b companys plc-5, plc-2 /PLC, plc-3 and slc-500 programs.2. Extension of Ethernet with further inclusion of Web technologies. Currently, one of the biggest trends in all process control areas is the expansion of Ethernet technology, and PLC is no exception. More and more PLC suppliers are now offering Ethernet interface components. The enterprise is planning to gradually connect all its automation control devices to enterprise-wide information systems. For industrial users, perhaps they have noticed the Ethernet for control family of control solutions, which rely more heavily on Ethernet and the Internet. Almost all PLC vendors offer Ethernet connectivity in some of their serialized products, and some companies have decided to embed Web servers completely inside their devices to fully demonstrate PLC performance characteristics. Industrial users can monitor the operation status of the control system from anywhere by taking advantage of the Web connection feature of PLC.中文翻译在高端市场，PLC与工业PC有得一拼，因为工业PC在数据集成和通信能力方面对用户的诱惑力很大。PC还引入了EthernetTCP/IP网络和与因特网互连的概念。但是现在，PLC制造商也能宣称，如果你想要这个，我们也能做到。欧洲的PLC领导厂商，西门子A&D和施耐德电气，都能提供功能强大的高端控制器系列，不管是PLC还是工业PC，并同时促进了PLC和工业PC领域的发展。西门子近期宣布S7-400PLC系列的重大性能提升，现在的CPU性能是以前的3倍，通信能力是以前的2倍。西门子还在其最高端的S7-400系列中增加了另一个创新：通信处理器，具有集成的、4端口的Ethernetswitch。不需要外部switch，是能用于小型以太网通信的经济型模式。但是，这种通信处理器真正的不同之处在于它是一个从现在向更高阶段发展的中间级，在更高阶段中，西门子将采用高端PLC和集成ProfinetV3switch的外部设备，能提供实时控制。施耐德电气已经大幅度的发展了高端CPU的性能，采用新的Unity编程软件，XML数据形式。在嵌入了webserver和多通信口后，新的CPU在功能上越来越像PC。集成的平台设计三菱电气PLC的进一步发展将在2至3年内，而现在已经初露端倪：多处理器和系统平台。从用户角度出发就意味着，能将功能块放在一块底板上，PLC和网络专家HughTasker认为，这些能包括标准PLC技术，但混合了运动控制和过程控制，或是全功能PC的性能，采用局部SCADA或SoftHMI方案技术。那发展方向是什么呢？他认为，对于用户，最大的好处在于控制系统结构的简化。不用再集成很多PLC，将他们连接，然后再运行和维护，现在的许多系统将减少PLC的个数，甚至就采用一个。这可以大大节省安装和维护时间，整个系统的耐用性也更强。他也推测了未来，在很长的一段时间，蓝牙技术和无线以太网技术的应用将更为广泛。它将先在小范围内起步，但在可靠性、耐用性和易接受性将获得提高，制造商还将有可能寻求无线技术的应用，也许某天他们连最基本的线缆都省去不用了。贝加莱自动化是控制产品供应商，提供工业PC，但相对于其他PLC制造者，它在PLC领域的时间也颇长。但他们却从来没有纠缠于PC与PLC孰强孰弱的问题，两者在共同发展。而且现在贝加莱看到了发展方向上的一些契机，也许两者的技术能不断融合。在过去的几年中，经典可编程逻辑控制器的发展始终向嵌入式PC技术发展，贝加莱业务经理AntonMeindl认为，PC技术有其优点-巨大的计算能力、与因特网技术的结合、快速以太网和USB接口，能结合传统的PLC系统的优点，如实用性强、耐用性强，以及模块性。欧姆龙的PLC+变频器欧姆龙推出的其第一款AC变频器3G3MV，可用于运动控制生产线。适用于小型的电动机控制（0.1到7.5kW）。它允许用户选择无传感矢量控制，能在低速提供高扭矩，在输出频率为1Hz时也能保证150%的扭矩。还具有I/O和通信功能。但是，在去年11月份，它增加了另一项功能，它可有些不寻常，欧姆龙增加了即插用的PLC模块，不只是一个附件，是一个完整的PLC，相当于欧姆龙的标准CPM2C-SPLC。使用双口RAM、PLC直接与变频器的I/O、数据和参数相连。PLC具有自己的I/O，能直接向变频器提供数据：编码输入、中断输出，以及数字式、脉冲式和PWM输出。欧姆龙认为，这种结合为网络或产品提供了理想的控制方案，能满足在位置和顺序方面的精确控制要求，也适用于制造业的多步骤包装生产线和智能输送线等。欧姆龙的PLC+变频器的组合如果用于泵的顺序控制器，在3个泵组成的系统中控制水压。PLC+变频器的组合对第一个泵进行连续的闭环控制，另外两个连在平行水管上的泵进行开/关控制。人机界面（MMI）可以进行监控，无线传输可将SMS信号传送至维护人员。PAC在美国在美国，市场战略有时甚至比技术本身更让人瞩目，2003年行业内有一个广为流行新词汇：可编程自动化控制器（ProgrammableAutomationController，PAC）。这个崭新的词汇源自于ARC咨询集团市场调查公司的CraigResnick，他认为，PLC相当活跃，而且发展良好，具很强的生命力。然而，PLC这个工业的有效工具正在许多方面不断改变，不断增加其魅力。自动化供应商正不断致力于PLC的开发，以迎合市场和特殊用户的需求。功能的增强促使了新系列的系统浮出水面。PAC基于开放的工业标准、具多领域功能、通用的开放平台以及高性能。ARC生造了这个词，以帮助用户定义应用需要，帮助制造商在谈到其产品时能更清晰。是否制造商会将产品名称从PLC改到PAC，还有待观察。但是，GEFanuc却没有丝毫犹豫，他们立刻接受了PAC的概念，而且在汉诺威展上公开宣布，其新的旗舰控制产品的名称为PACSystems。GEFanuc使用了这个名称，表达了其产品综合了传统PLC和PC硬件的优点，具有通用的编程环境，CimplicityMachineEdition软件。有一个单独的软件控制引擎，一个开发工具，多硬件目标编程。硬件不仅包括2个新的PACSystems处理器，还包括GEFanuc其他的自动化产品，如平板PC、嵌入式PC、MHI和其新的运动控制系统S2K。PACSystems代表了控制业的革新，它能使控制集中统一，而非各个完全无关的部件的拼凑，GEFanuc自动化（欧洲）的JohnPritchard.认为，一个引擎，加上一个开发工具，用户可以利用强大的工程环境进行多种应用。PAC你有我也有2003年11月Rockwell宣布，其为PAC技术的领导厂商，其产品ControlLogix和CompactLogixPLC事实上就是PAC。我们也看到了用户对控制系统数据的无限热情，用户可以收集安全、财务、质保程序等方面的信息，罗克韦尔自动化KenDeken认为，为满足用户的这个要求，用户需要控制器和业务系统之间的直接联系，任何时候都能提供信息。他认为，随着不断的发展，PAC将采用大量的方法以处理数据，并具有升级性，而在多项目控制、集成商务系统分析和生命周期成本管理等方面也能大踏步地前进。可编程序控制器技术取得了令人瞩目的成就，成为当今自动化领域中高速发展不断创新的一门学科。随着技术的日益成熟，可编程控制器已逐步发张发展成为以微处理器技术为核心，集计算机技术，自动化控制技术及通信技术于-体的工业控制装置。与网络技术及组态软件的配合，可编程控制器的应用如虎添翼。可编程序控制器在工业领域的应用十分广泛，既有单片机作为继电器逻辑电路替代品，又有作为现场控制的部件，又可以作为控制设备的核心部件。随着自动化程度的提高，它既可以作为现场控制的部件，又可以作为现场更高-级管理的控制部件。随着网络技术的发展，作为成熟技术，可编程控制器已被广泛应用到机械，冶金，化工，石化，水泥，食品饮料，制药等各个领域，极大地提高了劳动生产率和自动化程度。三菱，西门子是中国多个业务领域的领先工业解决方案供应商，在制造业自动化，流程工业自动化，运动控制，驱动，低压控制以及电气安装技术方面提供了各类创新，可靠，高效，和优质的产品。并全面提供系统的解诀方案和服务。产品涵盖范围广，在信息与通信，自动化控制，电力，交通，医疗，照明等各个行业领域处于领先优势。三菱，西门子控制技术，能够不断融入新技术，新方法，推陈出新。其中西门子控制技术进一步在e-制造和e-控制技术方面进行新的突破，新产品不断涌现，为各种各样的自动化控制设备提供了非常可靠的控制与应用。PLC的发展史在20世纪60年代，汽车生产流水线的自动控制系统基本都是由继电器控制装置构成的。当时汽车的每一次改型都直接导致继电器控制装置的重新设计安装。随着生产的发展，汽车型号更新的周期越来越短，这样，继电器控制装置就需要经常的重新设计和安装，十分费时，费工和费料，甚至阻碍了更新周期的缩短。为了改变这一现状，美国通用汽车公司在1969年公开招标，要求用新的控制装置取代继电器控制装置，并提出了十项招标指标，要求编程方便，现场可修改程序，维修方便，采用模块化结构等。1969年美国数字公司研制出第一台PLC，在美国通用汽车自动装配线上使用，获得了成功。这种新型的工业控制装置以其简单易懂，操作方便，可靠性高，通用灵活，体积小，使用寿命长等一系列优点，很快在美国其他工业领域推广应用，不久便成功地应用于食品，饮料等工业领域。这一新型工业控制装置的出现，也受到其他国家的高度重视。1971年日本从美国引进这项新技术，很快研制出日本第一台PLC。1973年西欧国家也研制出第一台PLC。我国从1974年开始研制，于1977年开始进入工业应用。进入20世纪80年代以来，随着大规模和超大规模集成电路等微电子技术的迅猛发展，以16位和少数32位微处理器构成的PLC得到了惊人的发展，使得PLC在设计，性能，价格以及应用方面都有了新的突破，不仅控制功能增强，功耗和体积减小，成本下降，可靠性提高，编程和故障检测更为灵活方便，而且远程I/O和通信网络，数据处理以及图像显示的发展，还包括方便的调试和测试工具，仿真工具等，已经使PLC普遍用于控制复杂的连续生产过程。目前，可编程序控制器已成为工厂自动化的三大支柱之一。1987年2月，国际电工委员会(IEC)对可编程控制器作了如下的定义：可编程控制器是一种数字运算操作的电子系统，专为在工业环境下的应用而设计。它采用一类可编程的存储库，用于其内部存储程序，执行逻辑运算，顺序控制，定时，计数和算术操作等面向客户的指令，并通过数字式或模拟式输入/输出，控制各种类型的机械或生产过程。可编程控制器及其有关外围设备，都按易于系统组成一个整体，易于扩充功能的原则设计。PLC之所以应用如此广泛，与它优越的性能是分不开的。PLC的主要特点：1可靠性高，抗干扰能力强在传统的继电器控制系统中，使用了大量的中间继电器等，由于器件的老化脱落，触电的抖动，接触不良等现象，大大降低了系统的可靠性。而在PLC控制系统中，大量的开关动作是由无触点的半导体电路完成的，因触点接触不良等原因造成的故障大为减少。另外，PLC在硬件和软件方面还采取了以下强有力的措施，来提高其可靠性。硬件方面，对所有的I/O接口电路均采用光电隔离，使工业现场的外电路与PLC内部电路之间电气上隔离；各模块均采用光电屏蔽措施，以防止辐射干扰；采用性能优良的开关电源并对供电系统和各输入电路均采用多种形式的滤波，以消除或抑制高频干扰；对所选用的器件进行严格的筛选；多采用模块结构，一旦某一模块有故障，可以迅速更换模块，从而尽可能缩短系统的故障停机时间。软件方面，PLC具有良好的自诊断能力，一旦电源或其他软，硬件发生异常情况，CPU立即采取有效措施，以防止故障扩大；PLC设置了监视定时器，如果程序循环的执行时间超过了规定值，则表明程序已进入了死循环，可以立即报警。对于大型的PLC系统，还可以采用由双CPU构成冗余系统或由三CPU构成表决系统，使系统的执行可靠性更进一-步提高。2丰富的I/0接口模块PLC针对不同的工业现场信号，如：交流或直流，开关量或模拟量，电压或电流，脉冲或电位，强电或弱电等信号，都能选择到相应的I/O模块与之匹配。对于工业现场的器件或设备，如：按钮，行程开关，接近开关，传感器及变送器，电磁线圈，控制阀等设备都能选择相应的I/O模块与之相连接。另外为了提高PLC的操作性能，它还有多种人机对话的接口模块；为了组成工业控制网络，还配备了多种通信联网的接口模块等等。3采用模块化结构为了适应各种工业控制需要，除了单元式的小型PLC以外，绝大多数PLC均采用模块化结构。PLC的各个部件，包括CPU，电源，I/0等均采用模块化设计，由机架及电缆将各模块连接起来，系统的规模和功能可根据用户的需要自行组合。4编程简单易学，系统的设计，调试周期短PLC的编程大多数采用类似于继电器控制线路的梯形图形式，对使用者来说，不需要具备计算机的专门知识，因此很容易被一般工程技术人员所理解和掌握。另外，由于PLC是通过程序实现对系统的控制，所以设计人员可以在实验室里设计和修改程序，还可以在实验室方便地进行系统的模拟及运行调试，使现场的工作量大为减少。5安装简单，维修方便PLC不需要专门的机房，可以在各种工业环境下直接运行。使用时只需将现场的各种设备与PLC相应的I/O端相连接，即可投入运行。PLC的故障率很低，且具有完善的自诊断和显示功能。当PLC或外部的输入装置和执行机构发生故障时，可以根据PLC各模块上的运行和故障指示装置或编程软件提供的信息，方便地查出故障的原因。由于采用模块化结构，因此一旦发生故障，用户可以通过更换模块的方法，使系统迅速恢复运行。总之，可编程控制器是一台计算机，它是专为工业环境应用而设计制造的。具有丰富的输入/输出接口，并且具有较强的驱动能力。但可编程序控制器产品并不针对某一-具体工业应用，在实际应用时，其硬件需根据实际需要进行选用配置，其软件需根据控制要求进行设计编程。PLC的工作原理1扫描工作方式PLC有两种基本的工作模式，即运行(RUN)模式与停止(STOP)模式。在运行模式，PLC通过反复执行用户程序来实现控制功能。为了使PLC得输出及时地响，应随时可能变化的输入信号，用户程序不是只执行一次，而是不断地重复执行，直到PLC停机或切换到STOP模式。2扫描周期PLC在Run工作模式时，执行一次扫描操作所需的时间称为扫描周期，其典型值约为1100ms。扫描周期与用户程序的长短、指令的种类和CPU执行指令的速度有很大的关系。当用户程序较长时，指令执行时间在扫描周期中占相当大的比例。有的编程软件或编程器可以提供扫描周期的当前值，有的还可以提供扫描周期的最大值和最小值。3输入/输出之后时间输入/输出之后时间又称系统响应时间，又指PLC的外部输入信号发生变化的时刻至它控制的有关外部输出信号发生变化的时间间隔，它由输入电路滤波时间、输出电路的之后时间和因扫描工作方式产生的滞后时间这三部分组成。输入模块的RC滤波电路用来滤除由输入端引入的干扰噪声，消除因外接输入触点动作时产生的抖动引起的不良影响，滤波电路的时间常数决定了输入滤波时间的长短，其典型值为10ms左右。输出模块的滞后时间与模块的类型有关。由扫描工作方式引起的滞后时间最长可能达两三个扫描周期。PLC总的响应延迟时间一般只有几十毫秒，对于一般的系统是无关紧要的。要求输入输出信号之间的滞后时间尽量短的系统，可以选用扫描速度快的PLC或采取其他措施。PLC的主要应用PLC的应用领域包括：专用机床、纺织机械、包装机械、通用机械工程应用、控制系统、机床、楼宇自动化、电器制造工业及相关产业等等。总之，PLC应用面广，功能强大，使用方便，已经成为当代工业自动化的主要支柱之一，在工业生产的所有领域得到了广泛的应用。两大典型的可编程控制器1西门子PLC：西门子PLC功能强大，系统稳定，性能质量好，市场占有率最高。个人感觉到主要基于西门子结构化的可编程方式，开放性好，支持多种通信协议。另外西门子适用多种人机界面和监控组态软件利于多厂家设备的通讯与集成，西门子做了很多功能块，减少了设计人员的负担。欧姆龙功能小一些，适用于小系统，编程也挺方便，价格稍低，但没有西门子稳定。2三菱PLC：三菱PLC和西门子PLC主要是变成理念不同，三菱是日系品牌，编程直观易懂，学习起来比较轻松，而西门子是德国品牌，指令比较抽象，学习难度较大，但指
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