外文翻译---可编程控制器技术讨论与未来发展
可编程序控制器外文文献翻译
英语原文:Programmable logic con trollerA programmable logic controller (PLC) or simply programmable controller is a digital computer used for automatio n of in dustrial processes, such as con trol of machi nery on factory assembly lin es. Un like gen eral-purpose computers, the PLC is desig ned for multiple in puts and output arrangements,extended temperature ranges, immunity to electrical noise, and resista nee to vibratio n and impact. Programs to con trol mach ine operati on are typically stored in battery-backed or non-volatile memory・ A PLC is an example of a real time system since output results must be produced in resp onse to in put con diti ons with in a boun ded time, otherwise uninten ded operatio n will result..FeaturesThe main differe nee from other computers is that PLC are armored for severe con diti on (dust, moisture, heat, cold, etc) and have the facility for extensive input/output (I/O) arrangements.These connect the PLC to sensors and actuators. PLC read limit switches, analog process variables (such as temperature and pressure),a nd the positions of complex positi oning systems・ Some eve n use mach ine visio n. On the actuator side, PLC operate electric motors, pn eumatic or hydraulic cyli nders, magn etic relays or sole no ids, or an alog outputs. The in put/output arran geme nts may be built into a simple PLC, or the PLC may have external I/O modules attached to a computer network that plugs into the PLC・PLC were inven ted as replaceme nts for automated systems that would use hun dreds or thousands of relays, cam timers, and drum sequencers. Often, a single PLC can be programmed to replace thousa nds of relays. Programmable con trailers were in itially adopted by the automotive manu facturi ng in dustry, where software revisio n replaced the re-wiri ng of hard-wired con trol pan els whe n producti on models cha nged.Many of the earliest PLC expressedall decision making logic in simple ladder logic whichappeared similar to electrical schematic diagrams. The electricia ns were quite able to trace out circuit problems with schematic diagrams using ladder logic. This program no tati on was chose n to reduce training dema nds for the existi ng tech nicians. Other early PLC used a form of in structi on list program ming, based on a stack-based logic solver.The functionality of the PLC has evolved over the years to include sequential relay con trol, moti on con trol, process con trol, distributed con trol systems and n etwork ing. The data han dli ng, storage, process ing power and com muni cati on capabilities of some moder n PLC are approximately equivale nt to desktop computers. PLC-like program ming comb ined with remote I/O hardware, allow a general-purpose desktop computer to overlap some PLC in certa in applicati ons.PLC compared with other con trol systemsPLC are well-adapted to a range of automati on tasks. These are typically in dustrial processes in manu facturi ng where the cost of develop ing and maintaining the automati on system is high relative to the total cost of the automation, and where changes to the system would be expected duri ng its operatio nal life. PLC contain in put and output devices compatible with in dustrial pilot devices and con trols; little electrical desig n is required, and the desig n problem cen ters on express ing the desired seque nee of operati ons in ladder logic no tati on. PLC applicati ons are typically highly customized systems so the cost of a packaged PLC is low compared to the cost of a specific custom-built controller design. On the other hand, in the case of mass-produced goods, customized con trol systems are econo mic due to the lower cost of the comp onen ts, which can be optimally chose n in stead of a ”ge neric" solution, and where the non・recurring engineering charges are spread over thousands of places.For high volume or very simple fixed automati on tasks, differe nt tech niq ues are used. For example, a con sumer dishwasher would be con trolled by an electromecha ni cal cam timer costing only a few dollars in production quantities.A microcontroller-based design would be appropriate where hundreds or thousandsof units willbe produced and so the development cost (design of power supplies and input/outputhardware) can be spread over many sales, and where the end-user would not n eed to alter the con trol. Automotive applicati ons are an example; millio ns of un its are built each year, and very few en d-users alter the program ming of these con trailers. However, some specialty vehicles such as tran sit busses econo mically use PLC in stead of custom-desig ned con trols, because the volumes are low and the developme nt cost would be unecono mic.Very complex process control, such as used in the chemical industry, may require algorithms and performs nee beyond the capability of eve n high-performa nee PLC. Very high - speed or precisi on con trols may also require customized solutio ns; for example, aircraft flight con trols.PLC may in elude logic for sin gle-variable feedback an alog con trol loop, a "proporti on al, in tegral, derivative" or ”PID con troller." A PID loop could be used to con trol the temperature of a manu facturi ng process, for example. Historically PLC were usually con figured with only a few analog control loops; where processesrequired hundreds or thousands of loops, a distributed con trol system (DCS) would in stead be used. However, as PLC have become more powerful, the boundary between DCS and PLC applications has become less clear-cut.Digital and an alog sig nalsDigital or discrete signals behave as binary switches, yielding simply an On or Off sig nal (1 or 0, True or False, respectively). Push butt on s, limit switches, and photoelectric sen sors are examples of devices providi ng a discrete sig nal. Discrete sig nals are sent using either voltage or current, where a specific range is designated asOn and another asOff. For example, a PLC might use 24 V DC I/O, with values above 22 V DC represe ntingOn, values below 2VDC represe nti ng Off, and in termediate values un defi ned. In itially, PLC had only discrete I/O.Analog signals are like volume controls, with a range of values between zero and full・ scale. These are typically in terpreted as in teger values (co un ts) by the PLC, with various ranges of accuracy depending on the device and the number of bits available to store the data. As PLC typicallyuse 16-bit sig ned binary processors, the in teger values are limited betwee n - 32,768 and +32,767. Pressure, temperature, flow, and weight are often represented by analog signals. Analog signals can use voltage or current with a magnitude proportional to the value of the process sig nal. For example, an an alog 4-20 m or 0 ・ 10 V in put would be conv erted into an in teger value of 0-32767.Curre nt in puts are less sen sitive to electrical no ise (i.e.from welders or electric motor starts) tha n voltage in puts.System scaleA small PLC will have a fixed nu mber of conn ecti ons built in for in puts and outputs. Typically, expa nsions are available if the base model does not have eno ugh I/O.Modular PLC have a chassis (also called a rack) into which is placed modules with differe nt functions. The processor and selecti on of I/O modules is custom for the particular application. Several racks can be administered by a single processor, and may have thousands of in puts and outputs・ A special high speed serial I/O link is used so that racks can be distributed away from the processor, reduc ing the wiri ng costs for large pla nts.PLC used in larger I/O systems may have peer-to-peer (P2P) com muni cati on betwee n processors. This allows separate parts of a complex process to have in dividual con trol while allowi ng the subsystems to co-ord in ate over the com muni cati on link. These com muni cati on links are also ofte n used for HMI (Huma Machi ne In terface) devices such as keypads or PC-type workstati ons. Some of today's PLC can com muni cate over a wide range of media in cludi ng RS-485, Coaxial, and eve n Ether net for I/O con trol at n etwork speeds up to 100m・Programmi ngEarly PLC, up to the mid・ 1980s, were programmed using proprietary programming pan els or special-purpose program ming term in als, which ofte n had dedicated fun cti on keys represe nting the various logical eleme nts of PLC programs. Programs were stored on cassette tape cartridges.Facilities for printing and documentation were very minimal due to lack of memory capacity. More rece ntly, PLC programs are typically writte n in a special applicati on on a pers onal computer, the n dow nl oaded by a direct-c onnection cable or over a n etwork to the PLC.The very oldest PLC used non-v olatile mag netic core memory but now the program is stored in the PLC either in battery-backed-up RAM or some other non-volatile flash memory.Early PLC were desig ned to replace relay logic systems. These PLC were programmed in "ladder logic**, which stron gly resembles a schematic diagram of relay logic. Moder n PLC can be programmed in a variety of ways, from ladder logic to more traditional programming languages such as BASIC and C. Another method is State Logic, a Very High Level Program ming Lan guage desig ned to program PLC based on State Tran siti on Diagrams.Recently, the International standard IEC 61131-3 has become popular. IEC 61131-3 currently defines five programming languages for programmable control systems: FBD (Function block diagram), LD (Ladder diagram), ST (Structured text, similar to the Pascal programming language), IL (Instruction list, similar to assembly Ianguage) and SFC (Seque ntial fun cti on chart). These tech niq ues emphasize logical orga ni zatio n of operati ons.While the fun dame ntal con cepts of PLC program ming are com mon to all manu facturers, differences in I/O addressing, memory organization and instruction sets mean that PLC programs are never perfectly interchangeable between different makers. Even within the same product line of a single manufacturer, different models may not be directly compatible.User in terfacePLC may n eed to in teract with people for the purpose of con figurati on, alarm report ing or everyday con trol. A Huma n-Mach ine In terface (HMI) is employed for this purpose. HMI' are also referred to as MMT (Ma n Mach ine In terface) and GUI (Graphical User In terface).A simple system may use butt ons and lights to in teract with the user. Text displays are available as well as graphical touch scree ns. Most moder n PLC can com muni cate over a n etwork to some other system, such as a computer running a SCADA (Supervisory Con trol And Data Acquisiti on) system or web browser.Com mun icatio nsPLC usually have built in com muni cati ons ports usually 9・Pi n RS232, and opti on ally for RS485 and Ether net. DF1 is usually in eluded as one of the com muni cati ons protocols. Other com muni cati ons protocols that may be used are listed in the List of automati on protocols.HistoryThe PLC was inven ted in resp onse to the n eeds of the America n automotive in dustry. Before the PLC, con trol, seque ncing, and safety in terlock logic for manu facturi ng automobiles was accomplished using relays, timers and dedicated closed-loop con trailers. The process for updati ng such facilities for the yearly model cha nge-over was very time consuming and expe nsive, as the relay systems n eeded to be rewired by skilled electricia ns. In 1968 GM Hydra (the automatic transmission division of General Motors) issued a request for proposal for an electro nic replaceme nt for hard-wired relay systems.The wi nning proposal came from Bedford Associates of Bedford, Massachusetts. The first PLC, desig nated the 084 because it was Bedford Associates' eighty-fourth project, was the result・Bedford Associates started a new compa ny dedicated to develop ing, manu facturi ng, selli ng, and servic ing this new product: Mod, which stood for One of the people whoworked on that project was Dick Morley, who is considered to be the "father" of the PLC. The brand was sold in 1977 to Gould Electr oni cs, and later acquired by Germa n Compa ny AEG and then by French Schn eider Electric, the curre nt owner.One of the very first 084 models built is now on display at headquarters in North Andover, Massachusetts .It was presented to by GM, when the unit was retired after nearly twenty years of unin terrupted service.The automotive industry is still one of the largest users of PLC, and still numbers some of its controller models such that they end with eighty-four. PLC are used in many different in dustries and machi nes such as packag ing and semic on ductor mach in es. Well known PLC brands are Toshiba, Sieme ns, Alle Bradley, ABB, Mitsubishi, Omro n, and Gen eral Electri・附录B英语翻译：可编程序控制器可编程逻辑控制器（PLC或干脆可编程序控制器是一个数字化的计算机用于自动化的工业生产过程，如控制机械的工厂装配生产线。
机电一体化专业外文翻译--PLC工业PC与DCS的特点与趋势
外文原文：The characteristics and trends of PLC, DCS and industrial PC At present, widely used in industrial automation systems of the three large industrial PC, DCS and PLC. Here, for their economic and technological standards and development trends described.First, the characteristics and Application of PLC1. PLC ApplicationEarly PLC (Programmable Logic Controller, PLC), mainly to replace relay logic control to achieve. With computer technology, communications technology and the rapid development of automatic control technology, the PLC will be the traditional relay control technology and the emerging computer technology and communications technology integration, with high reliability, strong function and flexible, Programming simple, easy to use and a series of advantages, as well as good performance of the industrial environment and control targets of performance in industrial production in a wide range of applications.1969, the United States Digital Equipment Corporation (DEC) developed the world's first programmable controller. Early separation from the programmable controller components and small and medium-sized integrated circuit component, the main function previously performed by the relay is completed sequence control, such as timing. The early 1970s, small size, strong function and cheaper microprocessors used PLC, makes the PLC function has been enhanced significantly. In terms of hardware, in addition to maintaining its original switch modules, has also increased the simulation module, remote I / O modules and special function modules all. In terms of software, easy to use PLC Electric staff in the ladder diagram programming language, in addition to maintaining the original logic functions, has also increased the arithmetic operations, data processing and transmission, communications and self-diagnostic capabilities. In the 1980's, the late, as ultra-large-scale integrated circuit technology is developing rapidly, microprocessor market a sharp price drop, the PLC makes the microprocessors used by the general improvement in grades. Furthermore, in order to further improve the processing speed of PLC, themanufacturer has developed a dedicated logic chip, greatly improving the PLC hardware and software functions.2. Characteristics PLCIn the developed industrial countries, PLC has been widely used in all industrial sectors. According to "The United States market information" World PLC and software market report, in 1995 the global software PLC and its economies of scale of about 5 billion US dollars [5]. As electronic technology and the development of computer technology, the PLC functions are greatly enhanced, with the following characteristics:(1) high reliability. PLC benefited from the high-reliability hardware and software on a series of anti-jamming measures and the cycle of its special scanning methods of work.(2) with rich I / O interface module. PLC for different industrial field signal and the corresponding I / O modules and industrial devices or equipment at the scene of a direct connection. In addition to improving performance, it also has a variety of man-machine dialogue interface modules to the industrial composition of local area networks, it also multiple communications network interface module.(3) modular structure. To meet the needs of various industrial control, in addition to a small PLC unit, the vast majority of PLC are modular structure. PLC various components, including the CPU, power supply, I / O, etc. is modular in design from the rack and cables will connect each module, the system's size and function in accordance with the needs of users of its own portfolio.(4) easy to learn programming. Most of the PLC programming relay control circuit similar to the ladder diagram form, the user, do not have computer expertise, it is easy to general engineering and technical personnel understand and master.(5) Installation is simple and easy maintenance. PLC does not require specialized equipment room in a variety of industrial environments can be directly run. Various modules are run and fault indication devices, user-friendly understanding of the operation and find fault. The modular structure, so any failure of a module, users can replace the module, allowing the system to rapidly resume operation.Second, the characteristics and Application of industrial PC1.Industrial PC industrial control applicationsIndustrial PC hardware and software support of a broad, diverse varieties can take full advantage of excellent graphical user interface capabilities, the industrial users an enormously attractive. Early PC but not suitable for industrial process control automation applications, such as increasing modified by strengthening the protection of the case, such as cooling damping taken measures to meet the industrial environment is the application of some of the requirements of the characteristics of its early development. In recent years, with the further integration of chips increase, the increase in functionality, system board technology, packaging components and surface mount technology improvements, and standard industrial bus, a standard operating system and graphical user interface software development, the Industrial PC development and application to enter its peak period, the complete machine reliability improved hardware, system software has continually improved, greatly enriched applications, in-depth industrial automation and control industries in various fields. According to incomplete statistics, in the industrial automation industrial PC usage in the total industrial control computer 65%, and an annual growth rate of 21 per cent continued to expand. PC manufacturing industry by buying rate of the PC market as a whole accounted for about 10 percent. In the industrial automation process control systems used in industrial management industry accounted for 44.1%, applied to the console operator of 36.4%, applied to the management of the quality of 18.8%, applied to monitor and control, engineers console, Data Acquisition System respectively of the total 18.2%, 12.6% and 11.1%.Industrial PC A notable feature is independent of configuration, but also with the DCS, PLC, CNC and other computer connected network. At present, almost all DCS, PLC manufacturers use industrial PC control system preparation procedures, more and more companies use industrial control system operator interface PC as a workstation. Formed by the industrial PC computer control system in the field of industrial automation process control play a very important role, has been outstanding for factory and workshop level process control, data acquisition, batch processing, quality control, automation and machine optimization and experts control, and other tasks.2. Main features of the PC industry(1) an industry-standard applicationIn order to enable different computer manufacturers can be linked to one another, as well as take full advantage of the market varied PC components and the functions provided by the module, industrial PC with standard interface, which not only required by the IEEE, DIN and ISO standards, to adopt AT (ISA), EISA and STD, VME, Multibus Ⅱ, and other bus standards. Industrial PC now has been widely adopted PCI, PCMCIA bus standard, the two industry-standard bus for improved performance and speed of a PC great role.(2) to take the necessary protection measuresApplications must be based on the control of environmental conditions on the PC industry adopt various protective measures, adapted from a project management departments to the scene operational control applications. Industrial PC must be able tolerance of the harsh conditions at the production environment, we must have good heat dissipation, ventilation, waterproof, dustproof, anti-jamming and anti-corrosion and anti-shock, anti-vibration and a series of protective features.(3) industrial operating systemMS-DOS because of lack of memory, unable to support multi-task, the lack of real-time features networking capacity and poor, has been basically not used. Along with the main computer chip, the rapid development of higher speed and better performance of industrial PC endless. In addition, almost all software development companies have shifted the focus will be open to the OS / 2, Windows and Unix, and other operating systems. Especially suitable for industrial process control automation real-time multi-tasking operating system application of Windows NT/2000 PC industry has generally become the mainstream operating system.(4) and automation equipment and communications systemsIndustrial PC should be able to with a variety of automated equipment and systems for effective communication, such as PLC, DCS, data acquisition systems, as well as on a management computer communication. With the continuous development of new technologies, due to open systems and system integration technology for thedevelopment needs of the PC industry these communications will be increasingly important role in the show.Standard communications network to the development of the industrial PC applications more open, and will enable its small computer pose a greater threat. MAP agreement to Ethernet-based communication networks to allow various computer systems communicate with each other directly. Different levels of automation in the mutual communication network systems, require separate handling of the communication channel. Industrial PC required monitoring level from the lower level data acquisition system and transmitted to a computer on.(5) the safe operation ofIn addition to the PC industry adopt various protective measures, the need for the operation of state industrial PC monitor, monitor the operation of computer systems and software, scheduled inspection procedures specified in the implementation of the cycle. Computer should be able to monitor the power supply, and failure or excessive deviation warning signal was issued.2.Industrial PC the status quo and development trendIndustrial PC now have a wide range of performance and functionality, low-grade industrial PC with a CRT terminal operators, high-grade industrial workstation with a PC. Thus, high-grade and low-grade industrial PC workstation performance and the price of overlap, the difference is disappearing, industrial PC and workstations increasingly blurred the boundaries between.Industrial PC workstation is the industrial automation process control system applications excellent choice, standard communication networks and the use of graphical operating system makes industrial PC and other equipment to effectively communicate. With 32-bit and 64-bit computer chips and the emergence of use, will be further enhanced industrial PC workstation functionality and performance, but also to a higher future direction.Industrial PC software is in the process of industrial automation control system of a key application. Hardware performance and the improvement of the drop in prices, as well as standardization and greater efficiency, better graphics and the use of the operating system to promote industrial PC software is an important factor indevelopment. At present, the rapid development of industrial PC software on the market has thousands of independent software development company can supply in the industrial PC running on industrial process control configuration software package to meet the rapid growth of the industrial user needs. Industrial PC application of industrial process control software packages are running on the configuration of OS / 2, Windows, and UNIX operating system standard. Industrial process control applications have emerged in large quantities, software development companies can provide a large number of industrial PC on the run for the PLC, DCS, such as industrial automation and control system configuration tools and graphical user interface software. Many PLC, DCS manufacturers development of the software configuration tool for automatic control system has become an important component. They used to replace dedicated industrial PC workstations, for the creation of real-time database, the control loop, graphic footage showed police records, real-time and historical trend data recording and process control, simulation, and other tasks. Now, for the process of surveillance and control, unit control, factory data collection, process optimization control, process control, simulation, statistical quality-control (SQC), the Statistical Process Control (SPC) and expert system for the control of industrial automation and control package has been tremendous developments. DAE applications such as IBM's software platform and the emergence of applications, the application provides a unified software development tool. Application Platform features from the PC-industry data exchange within the factory to the coordination of multiple systems, the standard data interface allows computer control equipment and exchange of data and information networks, for integrated information management and control system provides great convenience.Along with the standard graphical operating system continuously improve and develop, process control and industrial automation package greatly enriched, the industrial PC applications will increasingly strong.Three, the characteristics and Application of DCSDCS since its birth, after decades of continuous improvement, development and modernization has been very mature. Compared with the early, the scale of their systems, control functions, and other areas have been tremendous developments inchanges in the reliability, flexibility, adaptability, scalability, cost-effective integrated technical indicators have seen increased and improved. Has been widely used in petrochemical, pharmaceutical, energy, chemicals, paper, oil refining, metallurgy and food and beverage, and other industries, and has made very significant economic and social benefits. According to statistics, production facilities from analog instruments to DCS control the economic benefits can be achieved by the overall efficiency of 60%. DCS average payback period for 12, after the introduction of advanced control strategies can reduce the payback period of 0.5 to 1 year. DCS is today into various kinds of advanced control technology and equipment, and to the comprehensive integrated information management and automated process control systems, that is, CIMS direction.1. Development processFrom 1975, the DCS roughly experienced the 1975 ~ 1980, the first generation, from 1980 to 1985 the second generation, and after 1985 the third generation of three stages of development. Many manufacturers take DCS phased development strategy, adopted in the early systems continue to develop and improve, then launched with a variety of new features of the new system, the new system compatible with the original equipment homogeneous.Early DCS storage capacity small, relatively simple function. System modules include process control, process interface modules, CRT operator station, control computer and data Highway, Part 5. Its characteristics are using microprocessors to achieve decentralized control, CRT operator station and the process control unit separation operation carried out on display and remote control configuration. Honeywell company TDC-2000 is the first generation of the representation of DCS products.DCS mainly by second-generation local area networks, multi-function controllers, the computers, enhanced operator station, multifunction operator station, the connector between the network, system management module, and other components. Its characteristics are achieved more thoroughly decentralized control, decrease in the number of wiring, and anti-performance enhancement, improved level of standardization of hardware, high universality, function more comprehensive. Notonly strengthened control, and strengthening the system-wide information management, the introduction of local area networks and fiber optic communications technology. During this period the representation of the company products include Honeywell TDC-3000 and Westinghouse WDPF systems.DCS new generation is the most important feature of the process control, monitoring, management, scheduling organically integrate, through the use of open systems and standards such as MAP communication networks, such as Ethernet and Fieldbus solve different manufacturers equipment interconnection between issues. During the system is the development of a number of new features, using a 32 or 64-bit microprocessor, and a powerful workstations and enhanced the sequence control, volume control, the system can accommodate industrial PC and PLC; software greatly enriched by the standard graphical operating system platforms, and the user interface; introduction of the expert system, process control and other senior adaptive control function. Its products include Foxbor company representative I / A Series intelligent control system, ABB-Bailey INFI 90, ABB company Freelance 2000, RTP company RTP 2000/2200 HCS (Mixed Control System), and Yokogawa XL mXL, Honeywell Corporation TDC-3000 LCN / VCN-PM and Siemens PCS 7 systems.2. New characteristics and new development(1) Open to the DCS system to develop in the direction of CIMSAlong with the standard communication network and the development of fieldbus technology, a multi-level communications network DCS is the progressive realization of the full liberalization. The new system is the adoption of the ISO OSI model, the communication protocol to meet MAP / TOP or IEEE standards. In a backbone network, widely used MAP 3.0 agreement or ISO / OSI model; middle layer to use Mini MAP, IEEE 802.3, Ethernet or Proway; equipment is used at the lowest level fieldbus or bus to connect the transmitter. Open systems change the past DCS manufacturers self-contained closed situation, and make industrial users in the application of automation hardware and software have a greater choice.DCS is the new generation of multi-level multi-regional development. With multi-level communication networks as a tool for the entire factory or enterpriseinformation management and production control integration, the lowest level in the factory using digital equipment integrated into the scene DCS, in the solution of local senior management of various types of computer networks and interconnection, thus achieving optimal scheduling, decision-making, as well as the overall production process optimization. This production with the use of computer programs, product development, production processes and the material flow and information flow, integrated management system requirements for the development of CIMS. DCS use of open systems gradually to the direction of CIMS is integrated automation control system integrated a basic method.(2) workstations and graphical user interface features strengthen the operating stationWorkstations (including industrial PC workstations) and the use of graphical user interface, making recognizable DCS operator station. Many DCS manufacturers will be more DEC, SUN and companies such as Apollo Unix workstation tasks for the operator interface and control certain tasks, and corresponding use of the Motif, Penlook, X Window, OS / 2, Windows and other graphical user interface. Workstations cost-effective prices, high efficiency, and provides a user-friendly operator interface equipment. High-function workstations and high-resolution graphics equipment used, making operation to handle the greater amount of information, higher quality information processing, and use the mouse, touch screen, the cursor to the ball-type, as well as a number of other human-machine engineering.(3) a 32 or 64-bit processor hardware performance improved32 or 64-bit microcomputer development and use, is a milestone in the development of computer technology, the DCS hardware performance has a significant impact on the improvement. At present, most DCS has spent 32 or 64 computer to replace the original 16 aircraft, therefore, the corresponding process control stations and upgrade the operator stations. Series 86 using Intel processors Extended PC manufacturers now mainly uses the Pentium processor handling interface tasks while using M68 series producers are increasingly used in the 68020,68030 more processors. Most workstation processor performance to 5 ~ 50 M instructions / s. DCS process controllers use 32 or more processors, the performanceincrease than 2 times greater than before, the communication speed of the bus more than three times the network data transmission speed of 10,100,1000 Mb / s, the communications distance up to 20 km, I / O points up to 20,000 more, with the same scale system cheaper than the previous 30 to 40 percent.(4) Enhanced batch processing capacityEarly DCS mainly used for process control, DCS batch processing function has continually increased, and more and show its importance. DCS use menu operation and fill in the blank approach to system configuration and graphics features are suitable for batch processing applications. DCS vast majority of new products use the same controller can achieve continuous and batch process control. DCS logic operation in the software, such as Boolean functions more functions, enhanced Sequence Control System and volume control. If ABB-Bailey INFI 90 system uses a batch-processing language Batch 90 automatic processing of documents and internal Chaxi capacity, and function codes, ladder diagram mixed use, it can be directly read and write functional code and ladder diagram, allowing the interlock logic Disconnect in the order of control logic for implementation, simplifies the batch processing logic implementation.(5) software greatly enriched, an increase of senior controlIn the operating system, Windows NT and Unix open systems as a representative of a broad development prospects, its features include multi-user, multi-tasking, good character and can be transplanted networking capabilities. At present, real-time industrial automation in the Unix process control system of the openness of the structure play an important role, with the exception of DCS manufacturers for the development of their own operating systems, Unix and Windows NT are in a variety of DCS in the most widely used standard operating system.DCS configuration software modules used for the object-oriented language and the language of some system uses advanced programming language and graphics software. Configuration process normally use input and output, selection, calculation, logic, the police, limit the rate of order and control modules such as soft connections, a different control loop. Menu and fill in the blank-control operation makes configuration very easy.DCS control algorithm is continuously improve and develop. Apart from achieving PID, nonlinear, feedforward, Cascade, feedforward and feedback, but also the sequence control logic control and the ladder diagram, and the self-tuning PID parameters set, adaptive control. DCS manufacturers for the provision of various software modules, such as SPC / SQC (statistical-process control / statistical quality-control), CAD, artificial intelligence and expert systems, greatly enriched the DCS software library, an increase of high-level control system , the senior now on the market has reached thousands of control packages. Expert System, multivariable predictive control, fuzzy logic control and artificial neural network technology has been gradually practical and commercialization.DCS future software design and development will continue to focus on the following several aspects of the characteristics: modular program design, object-oriented programming; dedicated programming method used to achieve the X Window, voice recognition, etc., in order to industrial automation users provide more flexibility in the application of the operator interface.(6) intelligent sensors and other digital equipment to enter the scene of DCSAt present, the industrial process control automation company has introduced a large number of microprocessors, have both analog and digital signal output, and digital communication capabilities of intelligent field instrument. DCS manufacturers are using a variety of methods of the digital field devices integrated into its own system. Honeywell IACD such as two-way communication system for intelligent transmitter and TDC-3000 process controller connections and other components; ABB-Pele two-way communication system using 9600 baud FSK physical layer transmission, including its hardware input Fieldbus Fieldbus modules and terminal unit, software management procedures, including the transmitter and the transmitter function block; Moore company Mycro HART door connector can support 256 point-to-point connections or over 480 points connected intelligent transmitter; Foxbro companies addition to its own digital equipment integrated into the scene intelligent I / O system, also provides more than 60 other manufacturers, connecting doors connector.Fieldbus standard, from the bottom-up equipment to achieve the interconnection of different manufacturers, with the current technology development trend. At present, the development of fieldbus standard has been a high degree of international attention, is integrated industrial automation control system indispensable component. With the standardization of fieldbus communication technology development, the more intelligent DCS and control will shift downward, decentralized control equipment at the field level. They will DCS in the diagnosis and treatment provide a better platform, which enables more advanced DCS to open forms.(7) DCS further accommodate industrial PC and PLCIndustrial PC and PLC equipment as the DCS is now very common. DCS overwhelming majority of manufacturers has been providing industrial PC, PLC to DCS network connected to the hardware interface and application software.Industrial PC can make use of touch-screen and CRT window, a menu-driven approach may be to establish control strategy can also be used to achieve a plug on the motherboard and external communication. Through appropriate software and hardware interfaces, industrial PC with DCS in the process of connecting loop controller for loop control graphics. DCS industrial use as a PC operating station, programming terminals, surveillance, Taiwan, workstations, such as ABB-Pele, companies such as DCS Feixieer few years ago and the IBM PC compatible, DEC Professional, as well as 300 personal computers, etc. used for system configuration, monitoring, programming, and other tasks. Apart from some manufacturers developed a series of interface components and software, industrial PC as a DCS operator stations and other tasks, but also by third-party manufacturers such as OnSpec, and other process control packages.The relationship between the PLC and DCS is not only combine, and compete. Most are now combining DCS ladder logic programming technology, all PLC increases the simulation module to deal with the continuous production process. PLC through structural improvements, communications and networking capacity and control functions to increase and the introduction of similar DCS operator station, with monitoring computer operator interface. DCS also continuously enhance and batch processing capabilities, a small-scale, high-functional, modular direction. ThusDCS and PLC are gradually move closer, the two boundaries become increasingly blurred. They are functional and application of mutual penetration and integration. Thus, in many applications, it is difficult to distinguish between what is the PLC, which is the DCS. DCS are generally of the PLC interface can be connected to the PLC in the DCS. At present, a PLC-based DCS developed very quickly, discrete manufacturing and process industries tend to use hybrid control strategy PLC / DCS. Some of the same chassis system will be continuous control and PLC logic function together, not a separate PLC systems, such as the United States RTP 2000/2200 by the HCS that way, the system will be complete PLC and DCS features integrated together with the application of a control strategy Configuration Software NetSuite can complete all the control functions in the design and configuration.(8) Use of new technologies such as optical fiber communicationDCS in its development process and draw upon a variety of advanced technology. Optical fiber communications, high-density large-capacity disk surface mount technology, voice synthesis and recognition, multimedia, and other new technologies, as well as low-power CMOS RISC processor and other devices and has been in some of the new DCS has been fully applied. Optical fiber communications technology in the application of DCS more extensive. Because fiber is small in size, and large amounts of information, small signal attenuation and frequency bandwidth, anti-interference capability, transmission speed, the advantages of high reliability, high-speed access DCS used by the twisted pair and coaxial cable will gradually be replaced by fiber optic cable, making further enhance the effectiveness of communications systems. To further enhance system reliability, DCS communications bus network, as well as all levels of man-machine interface, controller interface at the scene and have been widely adopted redundant, fault-tolerant and fault isolation, and other protective measures.3. DCS to the future direction of CIMSDCS What is the future? A foreign process control experts to depict that image: DCS is disappearing, but the functions provided by the DCS will never disappear, they adapt to efficient, secure, real-time industrial process control automation needs of chassis control will continue to exist, but control room of the future will face。
【VIP专享】PLC中英文资料外文翻译
可编程控制器技术讨论与未来发展学生姓名：******所在院系：******所学专业：******导师姓名：******完成时间：******外文资料PLC technique discussion and future developmentWith the development of the times, today's technology is maturing, competition intensified; rely on manual operation does not satisfy the current industry outlook, there is no guarantee of higher quality requirements and high-tech corporate image.People saw in the production practice, automation to bring great convenience and product quality assurance, but also reduce the labor intensity, reducing the staff on the establishment in many complex production process is difficult to achieve target control, the overall optimization, optimal decision-making, skilled operatives, technicians or specialists, managers can easily determine and operate it, you can get satisfactory results. artificial intelligence research is the use of computers to achieve the target, the analog These intelligent behavior, through coordination of the human brain and a computer to combine human models for solving very complex problem of finding the best way.PLC's most important feature is: electrical engineer electrical hardware no longer spend too much scheming, as long as the button switch or sensor input connected to the PLC input point will solve the problem by connecting the output point contacts or relay to control the power of the boot device, and small power output devices can be connected directly.Contained within the PLC having a central processor of the CPU, and with an external I / O port expansion I / O interface and the memory addresses of three major components, CPU core is formed by one or more accumulators, which have the logical math capabilities, and can read the contents of the program memory to drive through the calculation of the corresponding memory and I / O interface; I / O port to the internal accumulator and external input and output systems together, and the relevant data stored in the program memory or data memory; memory can be I / O port input data stored in memory and transferred to the accumulator at work, and I / O interfaces, memory sub-ROM program memory and data memory RAM, ROM data can be permanently stored in memory, CPU and RAM only as a temporary calculated using the calculation buffer space.PLC immunity is extremely good, we do not have to care about the life and work of its harsh occasions, all of these issues are no longer the subject of our failure, and left us is concerned with how to take advantage of the PLC's internal resources tostrengthen our ability to control the device, so that our equipment is more flexible.PLC language is not what we imagine the assembly language or C language programming, instead of using the existing relay control of the ladder, making an electrical engineer in the preparation of the program is very easy to understand the language of the PLC, and many non- Electrical professionals and in-depth understanding of the PLC quickly.PLC communication has become increasingly reflect its value, in the communication between the PLC and the PLC, through information, communication and data sharing to ensure coordination between devices, has reached a complementary effect.PLC data transfer only the internal data to the other side of a consecutive addresses, we called it a table, the other PLC by reading data in the table to operate.The transmission of information has serial and parallel port lines of the points: the usual PLC is 8 machine, of course, there are 16 machines. When we send the data transmission can be a one to the other, you can also eight 8-bit send data to each other, one and eight difference is what we call the serial port and parallel port to send data to send data. Serial port speed is relatively slow, but as long as two or three port lines will solve the problem, and can use the phone line for remote control. The parallel port transmission speed is very fast, which is 256 times the serial port, a short distance advantage, because it is TTL level, generally limited to one meter range, it does not apply to long-distance data transmission, so the cost is too expensive.Many cases, we always like to use string and conversion chip for transmission, in which case we do not need to be overly complex register set, and direct data transfer instruction through the exchange of data, but not a very viable communication approach, because the transmit data when the PLC must have been waiting for the other side of your data output, it can not do other work.When you are reading a book, when you hear someone knocking at the door, you stop the hands of things, play to open the door, and knock on the door with a dialogue, this time the phone rings, you answer the phone schematically in take calls, back to knock on the door to continue with the dialogue, has been completed, you then continue to read your book, in which case we call it an interrupt, it has authority, also has priority, PLC have this kind of functionality. It is characterized by the operation of the device is that we may encounter during emergency incidents, we have to stop immediately the task at hand, to deal with more important things, this situation is thatwe often encounter, PLC to perform tasks in an emergency, always first save the current state, such as the program's address, CPU accumulator data, like when we went to open the door to note we are looking at the first few pages of the book or simply to make a sign, because we will have to continue to be followed to see the back of the book.CPU always in accordance with the wishes we should do, but you give it a wrong thing, it will do the same, which we must pay attention.Interrupt is not the only one, sometimes exist several interrupt, the interrupt priority level with them according to the person's request to perform higher-level interrupts. This will form the interrupt interrupt interrupt nesting. Of course, the level of disruption inside the PLC CPU based on a variety of resource-related, but also with the capacity of the stack size are also related.When we finished work a workpiece, a signal to the PLC, the PLC's internal counter is incremented by one to calculate the workload of our day, a simple counter to solve the problem, of course, they can also be kept in case of power failure data , prompting the data is not lost, it is our desire.PLC also has advanced features counter, when we accept some of the high-speed data, high speed mentioned here is in the microsecond-level data, such as bar code scanners constantly scan data, high-speed signal processor (DSP) calculated and so on, we will adopt to advanced counters to help us count. It is in the PLC program is executed once found senior counter corresponding interrupt, it will immediately put his work. After re-programming of the ladder program that we advanced in the implementation of the program counter will automatically perform the corresponding task, which will rise to a high level of senior counter a level.PLC development has grown from a single model into the era of communication networks and network with other industrial control panels and I / O card board easily be shared.Configuration software can connect all of these hardware through a more intuitive animated pictures to be controlled and can be controlled via the Internet in different places, such as the launch of Shenzhou V is using this approach to make the spaceship launch.Higher level of development we need to continue efforts to obtain. PLC has been around for a full impact on the generations, we have the experience from the previous generation to get more knowledge and lessons learned, to continue the development of PLC technology, to bring it to a higher tide.中文资料可编程控制器技术讨论与未来发展随着时代的发展,当今的技术也日趋完善、竞争愈演愈烈;单靠人工的操作已不能满足于目前的制造业前景,也无法保证更高质量的要求和高新技术企业的形象.人们在生产实践中看到,自动化给人们带来了极大的便利和产品质量上的保证,同时也减轻了人员的劳动强度,减少了人员上的编制.在许多复杂的生产过程中难以实现的目标控制、整体优化、最佳决策等,熟练的操作工、技术人员或专家、管理者却能够容易判断和操作,可以获得满意的效果.人工智能的研究目标正是利用计算机来实现、模拟这些智能行为,通过人脑与计算机协调工作,以人机结合的模式,为解决十分复杂的问题寻找最佳的途径PLC的最大特点在于：电气工程师已不再电气的硬件上花费太多的心计，只要将按钮开关或感应器的输入点连接到PLC的输入点上就能解决问题，通过输出点连接接触器或继电器来控制大功率的启动设备，而小功率的输出设备直接连接就可以。
【机械类文献翻译】PLC技术讨论和未来发展
英文原文PLC technique discussion and future developmentAlong with the development of the ages, the technique that is nowadays is also gradually perfect, the competition plays more more strong; the operation that list depends the artificial has already can't satisfied with the current manufacturing industry foreground, also can't guarantee the request of the higher quantity and high new the image of the technique business enterprise.The people see in produce practice, automate brought the tremendous convenience and the product quantities for people up of assurance, also eased the personnel's labor strength, reduce the establishment on the personnel. The target control of the hard realization in many complicated production lines, whole and excellent turn, the best decision etc., well-trained operation work, technical personnel or expert, governor but can judge and operate easily, can acquire the satisfied result. The research target of the artificial intelligence makes use of the calculator exactly to carry out, imitate these intelligences behavior, moderating the work through person's brain and calculators, with the mode that person's machine combine, for resolve the very complicated problem to look for the best pathWe come in sight of the control that links after the electric appliances in various situation, that is already the that time generation past, now of after use in the mold a perhaps simple equipments of grass-roots control that the electric appliances can do for the low level only;And the PLC emergence also became the epoch-making topic, adding the vivid software control through a very and stable hardware, making the automation head for the new high tide.The PLC biggest characteristics lie in: The electrical engineering teacher already no longer electric hardware up too many calculations of cost, as long as order the importation that the button switch or the importation of the sensors order to link the PLC up can solve problem, pass to output to order the conjunction contact machine or control the start equipments of the big power after the electric appliances, but the exportation equipments direct conjunction of the small power can.PLC internal containment have the CPU of the CPU, and take to have an I/ O for expand of exterior to connect a people's address and saving machine three big pieces to constitute, CPU core is from an or many is tired to add the machine to constitute, mathematics that they have the logic operation ability, and can read the procedure save the contents of the machine to drive the homologous saving machine and I/ Os to connect after pass the calculation; The I/ O add inner part is tired the input and output system of the machine and exterior link, and deposit the related data into the procedure saving machine or data saving machine; The saving machine can deposit the data that the I/ O input in the saving machine, and in work adjusting to become tired to add the machine and I/ Os to connect, saving machine separately saving machine RAM of the procedure saving machine ROM and datas, the ROM can can do deposit of the data permanence in the saving machine, but RAM only for the CPU computes the temporary calculation usage of hour of buffer space.The PLC anti- interference is very and excellent, our root need not concern its service life and the work situation bad, these all problems have already no longer become the topic that we fail, but stay to our is a concern to come to internal resources of make use of the PLC to strengthen the control ability of theequipments for us, make our equipments more gentle.PLC language is not we imagine of edit collected materials the language or language of Cs to carry on weaving the distance, but the trapezoid diagram that the adoption is original after the electric appliances to control, make the electrical engineering teacher while weaving to write the procedure very easy comprehended the PLC language, and a lot of non- electricity professional also very quickly know and go deep into to the PLC.Is PLC one of the advantage above and only, this is also one part that the people comprehend more and easily, in a lot of equipments, the people have already no longer hoped to see too many control buttons, they damage not only and easily and produce the artificial error easiest, small is not a main error perhaps you can still accept; But lead even is a fatal error greatly is what we can't is tolerant of. New technique always for bringing more safe and convenient operation for us, make we a lot of problems for face on sweep but light, do you understand the HMI? Says the HMI here you basically not clear what it is, also have no interest understanding, change one inside text explains it into the touch to hold or man-machine interface you knew, it combines with the PLC to our larger space.HMI the control not only only is reduced the control press button, increase the vivid of the control, more main of it is can sequence of, and at can the change data input to output the feedback with data, control in the temperature curve of imitate but also can keep the manifestation of view to come out. And can write the function help procedure through a plait to provide the help of various what lies in one's power, the one who make operate reduces the otiose error. Currently the HMI factory is also more and more, the function is also more and more strong, the price is also more and more low, the noodles of the usage are wide more and more. The HMI foreground can say that think ° to be good very.At a lot of situations, the list is is a smooth movement that can't guarantee the equipments by the control of the single machine, but pass the information exchanges of the equipments and equipments to attain the result that we want. For example fore pack and the examination of the empress work preface, we will arrive wrapping information feedback to examine the place, and examine the information of the place to also want the feedback to packing. Pass the information share thus to make both the chain connect, becoming a total body, the match of your that thus make is more close, at each other attain to reflect the result that mutually flick.The PLC correspondence has already come more more body now its value, at the PLC and correspondence between PLC, can pass the communication of the information and the share of the datas to guarantee that of the equipments moderates mutually, the result that arrive already to repair with each other. Data conversion the adoption RS232 between PLC connect to come to the transmission data, but the RS232 pick up a people and can guarantee 10 meters only of deliver the distance, if in the distance of 1000 meters we can pass the RS485 to carry on the correspondence, the longer distance can pass the MODEL only to carry on deliver.The PLC data transmission is just to be called a form to it in a piece of and continuous address that the data of the inner part delivers the other party, we, the PLC of the other party passes to read data in the watch to carry on the operation. If the data that data in the watch is a to establish generally, that is just the general data transmission, for example today of oil price rise, I want to deliver the price of the oil price to lose the oil allyon board, that is the share of the data; But take data in the watch for an instruction procedure that controls the PLC, that had the difficulty very much, for example you have to control one pedestal robot to press the action work that you imagine, you will draw up for it the form that a procedure combine with the data sends out to pass by.The form that information transport contain single work, the half a work and the difference of a works .The meaning of the single work also is to say both, a can send out only, but a can receive only, for example a spy he can receive the designation of the superior only, but can't give the superior reply; A work of half is also 2 and can can send out similar to accept the data, but can't send out and accept at the same time, for example when you make a phone call is to can't answer the phone, the other party also; But whole pair works is both can send out and accept the data, and can send out and accept at the same time. Be like the Internet is a typical example.The process that information transport also has synchronous and different step cent: The data line and the clock lines are synchronous when synchronous meaning lie in sending out the data, is also the data signal and the clock signals to be carry on by the CPU to send out at the same time, this needs to all want the specialized clock signal each other to carry on the transmission and connect to send, and is constrained, the characteristics of this kind of method lies in its speed very quick, but correspond work time of take up the CPU and also want to be long oppositely, at the same time the technique difficulty also very big. Its request lies in can't have an error margins in a data deliver, otherwise the whole piece according to compare the occurrence mistake, this on the hardware is a bigger difficulty. Applied more and more extensive in some appropriative equipments, be like the appropriative medical treatment equipments, the numerical signal equipments...etc., in compare the one data deliver, its result is very good.And the different step is an application the most extensive, this receive benefit in it of technique difficulty is opposite and want to be small, at the same time not need to prepare the specialized clock signal, its characteristics to lie in, its data is partition, the long-lost send out and accept, be the CPU is too busy of time can grind to a stop sex to work, also reduced the difficulty on the hardware, the data throw to lose at the same time opposite want to be little, we can pass the examination of the data to observe whether the data that we send out has the mistake or not, be like strange accidentally the method, tired addition and eight efficacies method etc., can use to helps whether the data that we examine to send out have or not the mistake occurrence, pass the feedback to carry on the discriminator.A line of transmission of the information contain a string of and combine the cent of: The usual PLC is 8 machines, certainly also having 16 machines. We can be an at the time of sending out the data a send out to the other party, also can be 88 send out the data to the other party, an and 8 differentiations are also the as that we say to send out the data and combine sends out the data. A speed is more and slowly, but as long as 2 or three lines can solve problem, and can use the telephone line to carry on the long range control. But combine the oscular transmission speed is very quick of, it is a string of oscular of 25600%, occupy the advantage in the short distance, the in view of the fact TTL electricity is even, being limited by the scope of one meter generally, it combine unwell used for the data transmission of the long pull, thus the cost is too expensive.Under a lot of circumstances we are total to like to adopt the string to combine the conversion chip to carryon deliver, under this kind of circumstance not need us to carry on to deposited the machine to establish too and complicatedly, but carry on the data exchanges through the data transmission instruction directly, but is not a very viable way in the correspondence, because the PLC of the other party must has been wait for your data exportation at the time of sending out the data, it can't do other works.When you are reading the book, you hear someone knock on door, you stop to start up of affair, open the door and combine to continue with the one who knock on door a dialogue, the telephone of this time rang, you signal hint to connect a telephone, after connecting the telephone through, return overdo come together knock on door to have a conversation, after dialogue complete, you continue again to see your book, this kind of circumstance we are called the interruption to it, it has the authority, also having sex of have the initiative, the PLC had such function .Its characteristics lie in us and may meet the urgently abrupt affairs in the operation process of the equipments, we want to stop to start immediately up of work, the whereabouts manages the more important affair, this kind of circumstance is we usually meet of, PLC while carry out urgent mission, total will keep the current appearance first, for example the address of the procedure, CPU of tired add the machine data etc., be like to to stick down which the book that we see is when we open the door the page or simply make a mark, because we treat and would still need to continue immediately after book of see the behind. The CPU always does the affair that should do according to our will, but your mistake of give it an affair, it also would be same to do, this we must notice.The interruption is not only a, sometimes existing jointly with the hour several inside break, break off to have the preferred Class, they will carry out the interruption of the higher Class according to person's request. This kind of breaks off the medium interruption to also became to break off the set. The Class that certainly break off is relevant according to various resources of CPU with internal PLC, also following a heap of capacity size of also relevant fasten.The contents that break off has a lot of kinds, for example the exterior break off, correspondence in of send out and accept the interruption and settle and the clock that count break off, still have the WDT to reset the interruption etc., they enriched the CPU to respond to the category while handle various business. Speak thus perhaps you can't comprehend the internal structure and operation orders of the interruption completely also, we do a very small example to explain.Each equipments always will not forget a button, it also is at we meet the urgent circumstance use of, that is nasty to stop the button. When we meet the Human body trouble and surprised circumstances we as long as press it, the machine stops all operations immediately, and wait for processing the over surprised empress recover the operation again.Nasty stop the internal I/ O of the internal CPU of the button conjunction PLC to connect up, be to press button an exterior to trigger signal for CPU, the CPU carries on to the I/ O to examine again, being to confirm to have the exterior to trigger the signal, CPU protection the spot breaks off procedure counts the machine turn the homologous exterior I/ O automatically in the procedure to go to also, be exterior interruption procedure processing complete, the procedure counts the machine to return the main procedure to continue to work.Have 1:00 can what to explain is we generally would nasty stop the button of exterior break off to rise to the tallest Class, thus guarantee the safety.When we are work a work piece, giving the PLC a signal, counting PLC inner part the machine add 1 tocompute us for a day of workload, a count the machine and can solve problem in brief, certainly they also can keep the data under the condition of dropping the electricity, urging the data not to throw to lose, this is also what we hope earnestly.The PLC still has the function that the high class counts the machine, being us while accept some datas of high speed, the high speed that here say is the data of the in all aspects tiny second class, for example the bar code scanner is scanning the data continuously, calculating high-speed signal of the data processor DSP etc., we will adopt the high class to count the machine to help we carry on count. It at the PLC carries out the procedure once discover that the high class counts the machine to should of interruption, will let go of the work on the hand immediately. The trapezoid diagram procedure that passes by to weave the distance again explains the high class for us to carry out procedure to count machine would automatic performance to should of work, thus rise the Class that the high class counts the machine to high one Class.Y ou heard too many this phrases perhaps:" crash", the meaning that is mostly is a workload of CPU to lead greatly, the internal resources shortage etc. the circumstance can't result in procedure circulate. The PLC also has the similar circumstance, there is a watchdog WDT in the inner part of PLC, we can establish time that a procedure of WDT circulate, being to appear the procedure to jump to turn the mistake in the procedure movement process or the procedure is busy, movement time of the procedure exceeds WDT constitution time, the CPU turn but the WDT reset the appearance. The procedure restarts the movement, but will not carry on the breakage to the interruption.The PLC development has already entered for network ages of correspondence from the mode of the one, and together other works control the net plank and I/ O card planks to carry on the share easily. A state software can pass all se hardwares link, more animation picture of keep the view to carries on the control, and cans pass the Internet to carry on the control in the foreign land, the blast-off that is like the absolute being boat No.5 is to adopt this kind of way to make airship go up the sky.The development of the higher layer needs our continuous effort to obtain.The PLC emergence has already affected a few persons fully, we also obtained more knowledge and precepts from the top one experience of the generation, coming to the continuous development PLC technique, push it toward higher wave tide.中文译文PLC技术讨论和未来发展随着时代的发展,当今的技术也日趋完善、竞争愈演愈烈，单靠人工的操作已不能满足于目前的制造业前景，也无法保证更高质量的要求和高新技术企业的形象。
plc外文翻译---谈plc的应用与发展-plc设计
附录On the application and development of PLC1.PLC definitionProgrammable logic controller, or PLC (Programmable logic Controller), refers to computer technology as the basis for the new industrial control devices. In 1987 the International Electrotechnical Commission (International Electrical Committee) standards promulgated by the PLC in the draft of the PLC made the following definition: "PLC is a specialist in industrial environments for the application of digital design and operation of electronic computing devices. It can be used in the preparation process memory, used in the implementation of its internal storage logical, sequential computing, timing, counting and arithmetic operations such as Operation The directive, and through digital or analog input and output, control various types of machinery or production process. PLC and its related peripheral equipment should be in accordance with the industrial control system easy to form a whole, easy to expand its functions to the principle and design. "2.PLC characteristicshigh reliability, strong anti-interference capabilityHigh reliability of electrical control equipment is the key to performance. PLC due to the introduction of modern large-scale integrated circuit technology, rigorous production process, the internal circuitry to take an advanced anti-jamming technology, high reliability. For example, Mitsubishi has produced an average of the F-Series PLC trouble-free time as much as 300,000 hours. Some use the redundant CPU PLC, the average working hours of trouble-free longer. PLC from the machine outside the circuit, the use of a PLC control system, and equal access for the scale of the relay systems, electrical wiring and switch contact has been reduced to hundreds or even percent, fault also greatly reduced.In addition, PLC with self-detection hardware failure, a failure to timely warning information. In the application software, applications can also peripheral devices into the fault diagnosis procedures, in addition to the system PLC and equipment outside the circuit fault diagnosis also be protected. In this way, the whole system is extremely high reliability is also not strange.equipped, with perfect functions, the applicabilityPLC to develop today, has formed a large, medium and small size of the serialization of various products. Can be used for various industrial control the scale of occasions. Apart from the logic processing functions, most of the modern PLC has a complete data computing power and can be used for a variety of digital control of the area. In recent years PLC emergence of a large number of functional units so that the PLC to infiltrate into a position of control, temperature control, CNC, and other industrial control. PLC communication capabilities coupled with the strengthening of human-computer interface technology and the development and use of various PLC control system very easily.easy to learn and use, welcomed by the engineering and technical personnel PLC as the general industrial computer, industrial and mining enterprises are facing the industrial equipment. It easy interface, easy programming language for engineering and technical staff. Ladder language and graphic symbols and expressions of the relay circuit very close, only a small number of switches of the PLC logic control orders can easily achieve the functions of the relay circuit. Is not familiar with the electronic circuits, computers do not understand the principles and compilation of language people use computers to carry out industrial control opened the door.system design, construction workload of small, maintenance-friendly, easy to transformPLC logic with memory instead of wiring logic, greatly reducing the wiring outside the control equipment, control systems design and construction of the much shorter cycle, while maintaining it has become easier. What is more important is to make the same equipment have been changes in procedures to change the production process possible. This is very suitable for many species, the small batch production of occasions. applicationsswitch to the logic of controlThis is the most basic PLC, the most extensive areas of application, which replaced the traditional relay circuits, and logic control, sequence control, can be usedsingle-control device, can also be used for more automation and control aircraft assembly line.analog controlIn the course of industrial production, many of the continuous changes, such as temperature, pressure, flow, level and speed are all analog. In order to deal with programmable analog controller, the need to achieve analog (Analog) and digital (Digital) between the A / D converter and D / A converter. PLC manufacturers are supporting the production of A / D and D / A converter module so that the programmable logic controller for analog control.Motion ControlPLC can be used circular motion or linear motion control. From the control of institutions targeted, the switching capacity for early direct I / O modules position sensor and executive bodies, now generally used for the movement control module. Such as stepper motor drive servo motor or the location of single or multi-axis control module. PLC the world's major manufacturers of products almost all movement control, widely used in all kinds of machinery, machine tools, robots, elevators, and other occasions.Process ControlRefers to the process control temperature, pressure, flow simulation of theclosed-loop control. As industrial computer, PLC to the preparation of a variety of control algorithms procedures, complete closed-loop control. PID regulator is generally closed-loop control system used in more conditioning methods. PID modules are large and medium-sized PLC, the PLC also has many small feature of this module. PID is running for the processing of PID subroutine. Process control in the metallurgical, chemical, heat treatment, boiler control, and other occasions have a very wide range of applications.Data ProcessingModern PLC with math (including matrix computing, computing functions, logic operation), data transmission, data conversion, sorting, look-up table, in operation, and other functions, to complete the data collection, analysis and treatment. These data can be stored in the memory of the reference value, the completion of a control operation, can also use the communication sent to other intelligent devices, or print them tabulation. Data processing for large-scale control systems such as unmanned control of flexible manufacturing systems; can also be used for process control systems, such as paper making, metallurgy, food industry in some large-scale control system.4. PLC of the situation at home and abroadThe world's first recognized the PLC is the 1969 . Digital Equipment Corporation (DEC) developed. Limited to conditions at the time of the components and computer development, early PLC mainly by discrete components and small and medium-scale integrated circuit components, can complete a simple logic control and timing, counting function. In the early 1970s a microprocessor. People will soon introduce its programmable logic controller, PLC an increase of computing, data transmission and processing functions, complete with a real computer features of industrial control devices. In order to facilitate familiar with the relay, contact the system engineering and technical staff, and the PLC adopt a similar ladder relay circuit as the main programming language, and will participate in the operation of the computer storage and processing components are named to the relay . At this time of the PLC for computer technologyand relay the concept of combining conventional control of the product.China's introduction of the PLC, applications, development, production is accompanied by reform and opening up began. The first is the introduction oflarge-scale use of the equipment in the PLC. Next in the production of business equipment and products continue to expand the application of the PLC. At present, China has its own can produce small and medium-sized PLC. East Electric Co., Ltd. Shanghai housing production CF Series, Hangzhou Machine Tool Factory production of electrical and DKK D series, Dalian Machine Tool Institute combination of the S-Series production, the Suzhou plant production of computers and other products YZ series has a certain scale And access to industrial products in the application. In addition, Wuxi Huaguang Company, Shanghai Rural Island companies such as Sino-foreign joint ventures in China is relatively well-known manufacturer of the PLC. It can be expected, with the deepening of China's modernization process, PLC in China will have a wider application of heaven and earth.5. PLC Future21 Century, PLC will have a greater development. From a technical perspective, the new achievements in computer technology will be applied to more programmable controllers on the design and manufacture, there will be faster and faster, greater storage capacity, more intelligent species emerged from the products on the scale , Will be further to the ultra-small and super-large direction, from the matching of products, the products of the species will be more rich and more complete specifications, the perfect man-machine interface, improved communications equipment will be better adapted to various industrial control Occasions demand from the market, the production of their respective countries and more varieties of products with international competition will intensify and break, there will be a few brand monopoly of the international market situation, there will be international common programming language from the network The development of the situation, the PLC and other industrial control of a large computer network control system is PLC technology development direction. The current computer distributed control system DCS (Distributed Control System) has been a lot of programmable logic controller applications. Along with the development of computer networks, automatic control programmable logic controller as a common network and international network an important part in industry and industrial fields outside of the increasing role.谈PLC的应用与发展1.可编程控制器的定义可编程控制器，简称PLC（Programmable logic Controller）,是指以计算机技术为基础的新型工业控制装置。
外文翻译PLC技术讨论与未来发展
中国地质大学长城学院本科毕业设计外文资料翻译系别信息工程系学生姓名刘硕专业电气工程及其自动化学号04309136 2012 年11 月17 日外文资料翻译译文PLC技术讨论与未来发展玛丽亚：约安尼季斯，高级会员，IEEE可编程逻辑控制器（PLC）或可编程控制器是一种用于机电过程自动化的数字计算机，如工厂的装配线，控制机械游乐设施，或照明灯具。
PLC应用在许多工业和机器。
不同于通用计算机，PLC是专为多个输入和输出的安排，扩展温度范围，免疫力电气噪声，抗振动和冲击。
程序控制机器操作通常存储在备用电池或非易失性存储器。
PLC要求实时系统的一个例子，因为输出必须响应输入条件的有限时间内，否则会导致意想不到的结果。
1历史。
PLC是应美国汽车制造行业的需要发明了。
可编程逻辑控制器最初由汽车行业软件修订取代硬连线控制面板重新布线时生产模式改变了。
PLC，控制，测序之前，和安全连锁逻辑制造汽车是使用数百或数千继电器，完成凸轮计时器，鼓音序器和专用闭环控制器。
对于每年更新的模型等设施转变过程是非常耗时和昂贵的，作为电工需要单独改变每个继电器。
1968 GM Hydramatic（通用汽车自动变速器分）发放了硬连线中继系统的电子替代方案的请求。
获奖的提案来自贝德福德联营公司的贝德福德，马萨诸塞州。
第一个PLC，指定084因为是贝德福德联营公司的四分之八十个项目，结果。
贝德福德联营公司开始了一个新的公司，致力于开发，生产，销售，和服务这一新产品：Modicon，它代表模块化数字控制器。
一个从事该项目的人是迪克莫利，谁被认为是“父亲”的PLC。
Modicon品牌销售在1977古尔德电子，后来被德国AEG公司，然后是法国施耐德电气，当前的所有者。
一个非常084建立的模型现在陈列在Modicon总部设在北安多佛，马萨诸塞州。
它是由通用汽车公司提出了Modicon，当单位是经过近二十年的不间断服务退休。
Modicon使用84的名字在其产品范围的结束，直到984出现。
【计算机专业文献翻译】可编程控制器技术讨论与未来发展
外文文献PLC technique discussion and future developmentAlong with the development of the ages, the technique that is nowadays is also gradually perfect, the competition plays more strong; the operation that list depends the artificial has already can't satisfied with the current manufacturing industry foreground, also can't guarantee the request of the higher quantity and high new the image of the technique business enterprise.The people see in produce practice, automate brought the tremendous convenience and the product quantities for people up of assurance, also eased the personnel's labor strength, reduce the establishment on the personnel. The target control of the hard realization in many complicated production lines, whole and excellent turn, the best decision etc., well-trained operation work, technical personnel or expert, governor but can judge and operate easily, can acquire the satisfied result. The research target of the artificial intelligence makes use of the calculator exactly to carry out, imitate these intelligences behavior, moderating the work through person's brain and calculators, with the mode that person's machine combine, for resolve the very complicated problem to look for the best pathWe come in sight of the control that links after the electric appliances in various situation, that is already the that time generation past, now of after use in the mold a perhaps simple equipments of grass-roots control that the electric appliances can do for the low level only; And the PLC emergence also became the epoch-making topic, adding the vivid software control through a very and stable hardware, making the automation head for the new high tide.The PLC biggest characteristics lie in: The electrical engineering teacher already no longer electric hardware up too many calculations of cost, as long as order the importation that the button switch or the importation of the sensors order to link thePLC up can solve problem, pass to output to order the conjunction contact machine or control the start equipments of the big power after the electric appliances, but the exportation equipments direct conjunction of the small power can.PLC internal containment have the CPU of the CPU, and take to have an I/ O for expand of exterior to connect a people's address and saving machine three big pieces to constitute, CPU core is from an or many is tired to add the machine to constitute, mathematics that they have the logic operation ability, and can read the procedure save the contents of the machine to drive the homologous saving machine and I/ Os to connect after pass the calculation; The I/ O add inner part is tired the input and output system of the machine and exterior link, and deposit the related data into the procedure saving machine or data saving machine; The saving machine can deposit the data that the I/ O input in the saving machine, and in work adjusting to become tired to add the machine and I/ Os to connect, saving machine separately saving machine RAM of the procedure saving machine ROM and dates, the ROM can do deposit of the data permanence in the saving machine, but RAM only for the CPU computes the temporary calculation usage of hour of buffer space.The PLC anti- interference is very and excellent, our root need not concern its service life and the work situation bad, these all problems have already no longer become the topic that we fail, but stay to our is a concern to come to internal resources of make use of the PLC to strengthen the control ability of the equipments for us, make our equipments more gentle.PLC language is not we imagine of edit collected materials the language or language of Cs to carry on weaving the distance, but the trapezoid diagram that the adoption is original after the electric appliances to control, make the electrical engineering teacher while weaving to write the procedure very easy comprehended the PLC language, and a lot of non- electricity professional also very quickly know and go deep into to the PLC.Is PLC one of the advantage above and only, this is also one part that the people comprehend more and easily, in a lot of equipments, the people have already nolonger hoped to see too many control buttons, they damage not only and easily and produce the artificial error easiest, small is not a main error perhaps you can still accept; But lead even is a fatal error greatly is what we can't is tolerant of. New technique always for bringing more safe and convenient operation for us, make we a lot of problems for face on sweep but light, do you understand the HMI? Says the HMI here you basically not clear what it is, also have no interest understanding, change one inside text explains it into the touch to hold or man-machine interface you knew, and it combines with the PLC to our larger space.HMI the control not only is reduced the control press button, increase the vivid of the control, more main of it is can sequence of, and at can the change data input to output the feedback with data, control in the temperature curve of imitate but also can keep the manifestation of view to come out. And can write the function help procedure through a plait to provide the help of various what lies in one's power, the one who make operate reduces the otiose error. Currently the HMI factory is also more and more, the function is also more and more strong, the price is also more and more low, and the noodles of the usage are wide more and more. The HMI foreground can say that think ° to be good very.At a lot of situations, the list is a smooth movement that can't guarantee the equipments by the control of the single machine, but pass the information exchanges of the equipments and equipments to attain the result that we want. For example fore pack and the examination of the empress work preface, we will arrive wrapping information feedback to examine the place, and examine the information of the place to also want the feedback to packing. Pass the information share thus to make both the chain connect, becoming a total body, the match of your that thus make is more close, at each other attain to reflect the result that mutually flick.The PLC correspondence has already come more body now its value, at the PLC and correspondence between PLCs, can pass the communication of the information and the share of the dates to guarantee that of the equipments moderates mutually, the result that arrive already to repair with each other. Data conversion the adoptionRS232 between PLC connect to come to the transmission data, but the RS232 pick up a people and can guarantee 10 meters only of deliver the distance, if in the distance of 1000 meters we can pass the RS485 to carry on the correspondence, the longer distance can pass the MODEL only to carry on deliver.The PLC data transmission is just to be called a form to it in a piece of and continuous address that the data of the inner part delivers the other party, we, the PLC of the other party passes to read data in the watch to carry on the operation. If the data that data in the watch is a to establish generally, that is just the general data transmission, for example today of oil price rise, I want to deliver the price of the oil price to lose the oil ally on board, that is the share of the data; But take data in the watch for an instruction procedure that controls the PLC, that had the difficulty very much, for example you have to control one pedestal robot to press the action work that you imagine, you will draw up for it the form that a procedure combine with the data sends out to pass by.The form that information transport contain single work, the half a work and the difference of a workers .The meaning of the single work also is to say both, a can send out only, but a can receive only, for example a spy he can receive the designation of the superior only, but can't give the superior reply; A work of half is also 2 and can send out similar to accept the data, but can't send out and accept at the same time, for example when you make a phone call is to can't answer the phone, the other party also; But whole pair works is both can send out and accept the data, and can send out and accept at the same time. Be like the Internet is a typical example.The process that information transport also has synchronous and different step cent: The data line and the clock lines are synchronous when synchronous meaning lie in sending out the data, is also the data signal and the clock signals to be carry on by the CPU to send out at the same time, this needs to all want the specialized clock signal each other to carry on the transmission and connect to send, and is constrained, the characteristics of this kind of method lies in its speed very quick, but correspond work time of take up the CPU and also want to be long oppositely, at the same timethe technique difficulty also very big. Its request lies in canting have an error margins in a dates deliver, otherwise the whole piece according to compare the occurrence mistake, this on the hardware is a bigger difficulty. Applied more and more extensive in some appropriative equipments, be like the appropriative medical treatment equipments, the numerical signal equipments...etc., in compare the one data deliver, its result is very good.And the different step is an application the most extensive, this receive benefit in it of technique difficulty is opposite and want to be small, at the same time not need to prepare the specialized clock signal, its characteristics to lie in, its data is partition, the long-lost send out and accept, be the CPU is too busy of time can grind to a stop sex to work, also reduced the difficulty on the hardware, the data throw to lose at the same time opposite want to be little, we can pass the examination of the data to observe whether the data that we send out has the mistake or not, be like strange accidentally the method, tired addition and eight efficacies method etc., can use to helps whether the data that we examine to send out have or not the mistake occurrence, pass the feedback to carry on the discriminator.A line of transmission of the information contains a string of and combine the cent of: The usual PLC is 8 machines, certainly also having 16 machines. We can be an at the time of sending out the data a send out to the other party, also can be 88 send out the data to the other party, an and 8 differentiations are also the as that we say to send out the data and combine sends out the data. A speed is more and slowly, but as long as 2 or three lines can solve problem, and can use the telephone line to carry on the long range control. But combine the ocular transmission speed is very quick of, it is a string of ocular of 25600%, occupy the advantage in the short distance, the in view of the fact TTL electricity is even, being limited by the scope of one meter generally, it combine unwell used for the data transmission of the long pull, thus the cost is too expensive.Under a lot of circumstances we are total to like to adopt the string to combine the conversion chip to carry on deliver, under this kind of circumstance not need us tocarry on to deposited the machine to establish too and complicatedly, but carry on the data exchanges through the data transmission instruction directly, but is not a very viable way in the correspondence, because the PLC of the other party must has been wait for your data exportation at the time of sending out the data, it can't do other works.When you are reading the book, you hear someone knock on door, you stop to start up of affair, open the door and combine to continue with the one who knock on door a dialogue, the telephone of this time rang, you signal hint to connect a telephone, after connecting the telephone through, return overdo come together knock on door to have a conversation, after dialogue complete, you continue again to see your book, this kind of circumstance we are called the interruption to it, it has the authority, also having sex of have the initiative, the PLC had such function .Its characteristics lie in us and may meet the urgently abrupt affairs in the operation process of the equipments, we want to stop to start immediately up of work, the whereabouts manages the more important affair, this kind of circumstance is we usually meet of, PLC while carry out urgent mission, total will keep the current appearance first, for example the address of the procedure, CPU of tired add the machine data etc., be like to stick down which the book that we see is when we open the door the page or simply make a mark, because we treat and would still need to continue immediately after book of see the behind. The CPU always does the affair that should do according to our will, but your mistake of give it an affair, it also would be same to do, this we must notice.The interruption is not only a, sometimes existing jointly with the hour several inside break, break off to have the preferred Class, they will carry out the interruption of the higher Class according to person's request. This kind of breaks off the medium interruption to also became to break off the set. The Class that certainly break off is relevant according to various resources of CPU with internal PLC, also following a heap of capacity size of also relevant fasten.The contents that break off has a lot of kinds, for example the exterior break off, correspondence in of send out and accept the interruption and settle and the clock thatcount break off, still have the WDT to reset the interruption etc., they enriched the CPU to respond to the category while handle various business. Speak thus perhaps you can't comprehend the internal structure and operation orders of the interruption completely also, we do a very small example to explain.Each equipment always will not forget a button, it also is at we meet the urgent circumstance use of, which is nasty to stop the button. When we meet the Human body trouble and surprised circumstances we as long as press it, the machine stops all operations immediately, and wait for processing the over surprised empress recover the operation again. Nasty stop the internal I/ O of the internal CPU of the button conjunction PLC to connect up, be to press button an exterior to trigger signal for CPU, the CPU carries on to the I/ O to examine again, being to confirm to have the exterior to trigger the signal, CPU protection the spot breaks off procedure counts the machine turn the homologous exterior I/ O automatically in the procedure to go to also, be exterior interruption procedure processing complete, the procedure counts the machine to return the main procedure to continue to work. Have 1:00 can what to explain is we generally would nasty stop the button of exterior break off to rise to the tallest Class, thus guarantee the safety.When we are work a work piece, giving the PLC a signal, counting PLC inner part the machine add 1 to compute us for a day of workload, a count the machine and can solve problem in brief, certainly they also can keep the data under the condition of dropping the electricity, urging the data not to throw to lose, this is also what we hope earnestly.The PLC still has the function that the high class counts the machine, being us while accept some dates of high speed, the high speed that here say is the data of the in all aspects tiny second class, for example the bar code scanner is scanning the data continuously, calculating high-speed signal of the data processor DSP etc., we will adopt the high class to count the machine to help we carry on count. It at the PLC carries out the procedure once discover that the high class counts the machine to should of interruption, will let go of the work on the hand immediately. The trapezoiddiagram procedure that passes by to weave the distance again explains the high class for us to carry out procedure to count machine would automatic performance to should of work, thus rise the Class that the high class counts the machine to high one Class.You heard too many this phrases perhaps:" crash", the meaning that is mostly is a workload of CPU to lead greatly, the internal resources shortage etc. the circumstance can't result in procedure circulate. The PLC also has the similar circumstance, there is a watchdog WDT in the inner part of PLC, we can establish time that a procedure of WDT circulate, being to appear the procedure to jump to turn the mistake in the procedure movement process or the procedure is busy, movement time of the procedure exceeds WDT constitution time, the CPU turn but the WDT reset the appearance. The procedure restarts the movement, but will not carry on the breakage to the interruption.The PLC development has already entered for network ages of correspondence from the mode of the one, and together other works control the net plank and I/ O card planks to carry on the share easily. A state software can pass all se hardwires link, more animation picture of keep the view to carries on the control, and cans pass the Internet to carry on the control in the foreign land, the blast-off that is like the absolute being boat No.5 is to adopt this kind of way to make airship go up the sky.The development of the higher layer needs our continuous effort to obtain. The PLC emergence has already affected a few persons fully, we also obtained more knowledge and precepts from the top one experience of the generation, coming to the continuous development PLC technique, push it toward higher wave tide.Knowing the available PLC network options and their best applications will ensure an efficient and flexible control system design.The programmable logic controller's (PLC's) ability to support a range of communication methods makes it an ideal control and data acquisition device for a wide variety of industrial automation and facility control applications. However, thereis some confusion because so many possibilities exist. To help eliminate this confusion, let's list what communications are available and when they would be best applied.To understand the PLC's communications versatility, let's first define the terms used in describing the various systems.ASCII: This stands for "American Standard Code for Information Interchange." As shown in Fig. 1, when the letter "A" is transmitted, for instance, it's automatically coded as "65" by the sending equipment. The receiving equipment translates the "65" back to the letter "A." Thus, different devices can communicate with each other as long as both use ASCII code.ASCII module: This intelligent PLC module is used for connecting PLCs to other devices also capable of communicating using ASCII code as a vehicle.Bus topology: This is a linear local area network (LAN) arrangement, as shown in Fig. 2A, in which individual nodes are tapped into a main communications cable at a single point and broadcast messages. These messages travel in both directions on the bus from the point of connection until they are dissipated by terminators at each end of the bus.CPU: This stands for "central processing unit," which actually is that part of a computer, PLC, or other intelligent device where arithmetic and logical operations are performed and instructions are decoded and executed.Daisy chain: This is a description of the connection of individual devices in a PLC network, where, as shown in Fig. 3, each device is connected to the next and communications signals pass from one unit to the next in a sequential fashion.Distributed control: This is an automation concept in which portions of an automated system are controlled by separate controllers, which are located in close proximity to their area of direct control (control is decentralized and spread out over the system).Host computer: This is a computer that's used to transfer data to, or receive data from, a PLC in a PLC/computer network.Intelligent device: This term describes any device equipped with its own CPU.I/O: This stands for "inputs and outputs," which are modules that handle data to the PLC (inputs) or signals from the PLC (outputs) to an external device.Kbps: This stands for "thousand bits per second," which is a rate of measure for electronic data transfer.Mbps: This stands for "million bits per second."Node: This term is applied to any one of the positions or stations in a network. Each node incorporates a device that can communicate with all other devices on the network.Protocol: The definition of how data is arranged and coded for transmission on a network.Ring topology. This is a LAN arrangement, as shown in Fig. 2C, in which each node is connected to two other nodes, resulting in a continuous, closed, circular path or loop for messages to circulate, usually in one direction. Some ring topologies have a special "loop back" feature that allows them to continue functioning even if the main cable is severed.RS232. This is an IEEE standard for serial communications that describes specific wiring connections, voltage levels, and other operating parameters for electronic data communications. There also are several other RS standards defined.Serial: This is an electronic data transfer scheme in which information is transmitted one bit at a time.Serial port: This the communications access point on a device that is set up for serial communications.Star topology. This is a LAN arrangement in which, as shown in Fig. 2B, nodes are connected to one another through a central hub, which can be active or passive. An active hub performs network duties such as message routing and maintenance. A passive central hub simply passes the message along to all the nodes connected to it.Topology: This relates to a specific arrangement of nodes in a LAN in relation to one another.Transparent: This term describes automatic events or processes built into a system that require no special programming or prompting from an operator.Now that we're familiar with these terms, let's see how they are used in describing the available PLC network options.PLC network optionsPLC networks provide you with a variety of networking options to meet specific control and communications requirements. Typical options include remote I/O, peer-to-peer, and host computer communications, as well as LANs. These networks can provide reliable and cost-effective communications between as few as two or as many as several hundred PLCs, computers, and other intelligent devices.Many PLC vendors offer proprietary networking systems that are unique and will not communicate with another make of PLC. This is because of the different communications protocols, command sequences, error-checking schemes, and communications media used by each manufacturer.However, it is possible to make different PLCs "talk" to one another; what's required is an ASCII interface for the connection(s), along with considerable work with software.Remote I/0 systemsA remote I/O configuration, as shown in Fig. 4A, has the actual inputs andoutputs at some distance from the controller and CPU. This type of system, which can be described as a "master-and-slave" configuration, allows many distant digital and analog points to be controlled by a single PLC. Typically, remote I/Os are connected to the CPU via twisted pair or fiber optic cables.Remote I/O configurations can be extremely cost-effective control solutions where only a few I/O points are needed in widely separated areas. In this situation, it's not always necessary, or practical for that matter, to have a controller at each site. Nor is it practical to individually hard wire each I/O point over long distances back to the CPU. For example, remote I/O systems can be used in acquiring data from remote plant or facility locations. Information such as cycle times, counts, duration or events, etc. then can be sent back to the PLC for maintenance and management reporting.In a remote I/O configuration, the master controller polls the slaved I/O for its current I/O status. The remote I/O system responds, and the master PLC then signals the remote I/O to change the state of outputs as dictated by the control program in the PLC's memory. This entire cycle occurs hundreds of times per second.Peer-to-peer networksPeer-to-peer networks, as shown in Fig. 4B, enhance reliability by decentralizing the control functions without sacrificing coordinated control. In this type of network, numerous PLCs are connected to one another in a daisy-chain fashion, and a common memory table is duplicated in the memory of each. In this way, when any PLC writes data to this memory area, the information is automatically transferred to all other PLCs in the network. They then can use this information in their own operating programs.With peer-to-peer networks, each PLC in the network is responsible for its own control site and only needs to be programmed for its own area of responsibility. This aspect of the network significantly reduces programming and debugging complexity; because all communications occur transparently to the user, communications programming is reduced to simple read-and-write statements.In a peer-to-peer system, there's no master PLC. However, it's possible to designate one of the PLCs as a master for use as a type of group controller. This PLC then can be used to accept input information from an operator input terminal, for example, sending all the necessary parameters to other PLCs and coordinating the sequencing of various events.Host computer linksPLCs also can be connected with computers or other intelligent devices. In fact, most PLCs, from the small to the very large, can be directly connected to a computer or part of a multi drop host computer network via RS232C or RS422 ports. This combination of computer and controller maximizes the capabilities of the PLC, for control and data acquisition, as well as the computer, for data processing, documentation, and operator interface.In a PLC/computer network, as shown in Fig. 4C, all communications are initiated by the host computer, which is connected to all the PLCs in a daisy-chain fashion. This computer individually addresses each of its networked PLCs and asks for specific information. The addressed PLC then sends this information to the computer for storage and further analysis. This cycle occurs hundreds of times per second.Host computers also can aid in programming PLCs; powerful programming and documentation software is available for program development. Programs then can be written on the computer in relay ladder logic and downloaded into the PLC. In this way, you can create, modify, debug, and monitor PLC programs via a computer terminal.In addition to host computers, PLCs often must interface with other devices, such as operator interface terminals for large security and building management systems. Although many intelligent devices can communicate directly with PLCs via conventional RS232C ports and serial ASCII code, some don't have the software ability to interface with individual PLC models. Instead, they typically send andreceive data in fixed formats. It's the PLC programmer's responsibility to provide the necessary software interface.The easiest way to provide such an interface to fixed-format intelligent devices is to use an ASCII/BASIC module on the PLC. This module is essentially a small computer that plugs into the bus of the PLC. Equipped with RS232 ports and programmed in BASIC, the module easily can handle ASCII communications with peripheral devices, data acquisition functions, programming sequences, "number crunching," report and display generation, and other requirements.Access, protocol, and modulation functions of LANsBy using standard interfaces and protocols, LANs allow a mix of devices (PLCs, PCs, mainframe computers, operator interface terminals, etc.) from many different vendors to communicate with others on the network.Access: A LAN's access method prevents the occurrence of more than one message on the network at a time. There are two common access methods.Collision detection is where the nodes "listen" to the network and transmit only if there are no other messages on the network. If two nodes transmit simultaneously, the collision is detected and both nodes retransmit until their messages get through properly.Token passing allows each node to transmit only if it's in possession of a special electronic message called a token. The token is passed from node to node, allowing each an opportunity to transmit without interference. Tokens usually have a time limit to prevent a single node from tying up the token for a long period of time.Protocol: Network protocols define the way messages are arranged and coded for transmission on the LAN. The following are two common types.Proprietary protocols are unique message arrangements and coding developed by a specific vendor for use with that vendor's product only.。
可编程逻辑控制器(PLC )外文翻译
可编程逻辑控制器〔PLC 〕1．PLC介绍众所周知，科技世界里只有一个永恒真理，那就是变化。
这在可编程逻辑控制器〔PLC〕及其各种应用的开展过程中尤为明显。
自从三十多年前将PLC引进以来，PLC 已经在广泛的工业领域中成为几十万控制系统的根底。
从本质上讲，PLC是一种用高度专业化语言编程的工业计算机，并继续受益于计算机和信息技术领域的技术进步，它的最突出之处是小型化和通信功能。
可编程逻辑控制器I/O通道规那么包括所有的输入触点和输出触点，扩展能力和最大数量的通道。
触点数量是输入点和输出点的总和。
PLC可以指定这些值的任何可能的组合。
扩展单元可以被堆栈或互相连接来增加总的控制能力。
最大数量的通道是在一个扩展系统中输入和输出通道的最大总数量。
PLC系统规那么包括扫描时间，指令数量，数据存储和程序存储。
扫描时间是 PLC需要的用来检测输入输出模块的时间。
指令是用于PLC软件〔例如数学运算〕的标准操作。
数据存储是存储数据的能力。
程序存储是控制软件的能力。
用于可编程逻辑控制器的输入设备包括DC，AC，中间继电器，热电偶，RTD，频率或脉冲，晶体管和中断信号输入；输出设备包括DC，AC，继电器，中间继电器，频率或脉冲，晶体管，三端双向可控硅开关元件；PLC的编程设备包括控制面板，手柄和计算机。
可编程逻辑控制器用各种软件编程语言来控制。
这些语言包括IEC61131-3，顺序执行表〔SFC〕，动作方块图〔FBD〕，梯形图〔LD〕，结构文本〔ST〕，指令序列〔IL〕，继电器梯形图〔RIL〕，流程图，C语言和Basic语言。
IEC61131-3编程环境能支持五种语言，用国际标准加以标准，分别为SFC，FBD，LD，ST和IL。
这便允许了多卖主兼容性和多种语言编程。
SFC是一种图表语言，它提供了编程顺序的配合，就能支持顺序选择和并列选择，二者择其一即可。
FBD用一种大的运行库，以图表形式建立了一些复杂的过程。
标准数学和逻辑运行可以与用户交流和接口运行相结合。
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毕业论文（设计）外文翻译题目：可编程控制器技术讨论与未来发展系部名称：机械工程系专业班级：学生姓名：学号：指导教师：教师职称：2011年03月11日中文翻译可编程控制器技术讨论与未来发展随着时代的发展,当今的技术也日趋完善、竞争愈演愈烈;单靠人工的操作已不能满足于目前的制造业前景,也无法保证更高质量的要求和高新技术企业的形象。
人们在生产实践中看到,自动化给人们带来了极大的便利和产品质量上的保证,同时也减轻了人员的劳动强度,减少了人员上的编制.在许多复杂的生产过程中难以实现的目标控制、整体优化、最佳决策等,熟练的操作工、技术人员或专家、管理者却能够容易判断和操作,可以获得满意的效果.人工智能的研究目标正是利用计算机来实现、模拟这些智能行为,通过人脑与计算机协调工作,以人机结合的模式,为解决十分复杂的问题寻找最佳的途径。
我们在各种场合看到了继电器连接的控制，那已经是时代的过去，如今的继电器只能作为低端的基层控制模块或者简单的设备中使用到；而PLC的出现也成为了划时代的主题，通过极其稳定的硬件穿插灵活的软件控制，使得自动化走向了新的高潮。
PLC的最大特点在于：电气工程师已不再电气的硬件上花费太多的心计，只要将按钮开关或感应器的输入点连接到PLC的输入点上就能解决问题，通过输出点连接接触器或继电器来控制大功率的启动设备，而小功率的输出设备直接连接就可以。
PLC的内部包含了具有中央处理器的CPU，并带有外部I/O口扩展的I/O接口地址和存储器三大块组成，CPU的核心是由一个或者多个累加器组成，它们具有逻辑的数学运算能力，并能读取程序存储器的内容通过计算后去驱动相应的存储器和I/O接口；I/O口将内部累加器和外部的输入和输出系统连接起来，并将相关的数据存入程序存储器或者数据存储器中；存储器可以将I/O口输入的数据存入存储器中，并在工作时调转到累加器和I/O接口上，存储器分程序存储器ROM和数据存储器RAM,ROM可以将数据永久的存入存储器中，而RAM只能作为CPU计算时临时计算使用的缓冲空间。
PLC的抗干扰是极其优秀的，我们根本不用去关心它的使用寿命和工作场合的恶劣，这些所有的问题已不再成为我们失败的主题，而留给我们的是关心如何来利用PLC的内部资源为我们加强设备的控制能力，使我们的设备更加的柔性。
PLC的语言并不是我们所想象的汇编语言或C语言来进行编程，而是采用原有的继电器控制的梯形图，使得电气工程师在编写程序时很容易就理解了PLC的语言，而且很多的非电气专业人士也对PLC很快认识并深入。
以上仅仅是PLC的优点之一，这也是人们比较容易理解的一部分，在很多的设备中，人们已不再希望看到太多的控制按钮，它们不但容易损坏而且极易产生人为的失误，小的并不是主要的失误也许你还能够接受；但过大的甚至是致命的失误是我们无法容忍的。
新的技术总是为了给我们带来更安全和便捷的操作，使得我们面临的一大堆问题一扫而光，你有了解过HMI吗？这里说HMI你根本不清楚它是什么，也没有兴趣了解，换一个中文把它说明为触摸屏或者人机界面你就知道了，它和PLC的结合给了我们更大的空间。
HMI控制不仅仅是减少了控制按钮，增加控制的灵活性，更主要的它是可顺序性的，而且在能够改变数据输入和数据输出反馈，在温度控制曲线的模拟也能直观的显示出来。
并且能够通过编写功能帮助程序来提供各种力所能及的帮助，使得操作者减少不必要的失误。
HMI的厂商目前也越来越多，功能也越来越强，价格也越来越低，使用的面越来越广。
HMI的前景可以说十分的看好。
在很多场合，单靠单机的控制是无法保证设备的顺畅运行，而通过设备与设备的信息交流达到我们想要的效果。
比如在前包装和后工序的检测，我们就要将包装的信息反馈到检测处，而检测处的信息也要反馈到包装来。
这样通过信息共享来使得两者之间链接起来，形成一个共体，从而使的两者间的配合更加的紧密，在彼此间达到映影相挥的效果。
PLC的通信已经愈来愈体现它的价值，在PLC与PLC之间的通信，能够通过信息的沟通和数据的共享来保证设备之间的相互协调，已达到互补的效果。
PLC之间的数据转换采用RS232接口来传送数据，而RS232接口只能保证10米的传输距离，如果在1000米的距离内我们可以通过RS485来进行通信，更长的距离只能通过MODEL来进行传输。
PLC的数据传送只是将内部的数据传送到对方的一块连续的地址中，我们把它称为一个表，对方的PLC通过读取表中的数据来进行操作。
如果表中的数据是一个一般设置的数据的话，那只是一般的数据传送，比如今天的油价上升了，我要把油价的价格传送到所有的输油机上，那就是数据的共享；而当表中的数据是一段控制PLC的指令程序，那就很有难度了，比如你要控制一台机器人来按你想象的动作工作，你会给它编制一段程序并以数据的形式发送过去。
信息输送的形式有单工位、半双工位和全双工位的分别。
单工位的意义也就是说两者之间，一个只能发送，而一个只能接收，比如一个特务他只能接收上司的指示，而无法给上司回复；半双工位也就是两个能都能发送和接受数据，但不能同时发送和接受，比如你打电话时是不能接电话,对方也一样；而全双工位是两者之间都能发送和接受数据，并可同时发送和接受。
像互联网就是典型的例子。
信息输送的过程也有同步和异步之分：同步的意义在于发送数据时数据线和时钟线是同步的，也就是数据信号和时钟信号同时由CPU进行发送，这需要彼此都要专门的时钟信号来进行传送和接送，并且是强制性的，这种方法的特点在于它的速度极快、但相应占用CPU的工作时间也相对的要长、同时技术难度也非常的大。
它的要求在于在一帧的数据传送中不能有一位的误差，不然的话整个数据将发生错误，这在硬件上是一个比较大的难度。
在一些专用的设备中应用的越来越广泛，像专用的医疗设备、数字信号设备等，在比较单一数据的传输中，它的效果非常的好。
而异步是应用范围最广泛的，这得益于它的技术难度相对要小、同时不需要配制专门的时钟信号、它的特点在于，它的数据是间隔性的，离散性的发送和接受，当CPU太忙的时候可以停顿性去工作，在硬件上也减少了难度，同时数据的丢失相对要少，我们可以通过数据的检测来观察我们发送的数据是否有错误，像奇偶法、累加法和八位效验法等，都可以用来帮助我们检测发送的数据是否有错误发生，通过反馈来进行辨别。
信息的传送口线有串口和并口之分：通常的PLC是8位机，当然也有16位机。
我们在发送数据的时候可以是一位一位的发送给对方，也可以8位8位的将数据发送到对方，一位和8位区别也就是我们所说的串口发送数据和并口发送数据。
串口速度比较慢，但只要两条或者三条口线就能解决问题，并能借用电话线来进行远程控制。
而并口的传送速度是极快的，它是串口的256倍，在短距离占有优势，由于是TTL电平，一般限于1米的范围，它并不适用于长距离的数据传送，这样成本太昂贵了。
很多的情况下我们总喜欢采用串并转换芯片来进行传输，这种情况下不需要我们进行过于复杂的寄存器设置了，而直接通过数据传送指令进行数据交流，但在通信中并不是一个十分可行的办法，因为在发送数据的时候对方的PLC必须一直等待你的数据输出，它不能去做其他的工作。
当你在看书的时候，你听到有人敲门、你停下手上的事情、去打开门、并同敲门者对话、这个时候电话响了、你示意接个电话、在接完电话后、回过头来同敲门者继续对话、对话完毕后、你再继续看你的书，这种情况我们把它称为中断，它具有权威性，也具有优先性，PLC具备了这样的功能。
它的特点在于我们在设备的操作过程中可能会遇到紧急的突发事件，我们要立刻的停下手上的工作，去处理更重要的事情，这种情况是我们经常所遇到的，PLC在去执行紧急的任务时，总会先保存目前的状态，比如程序的地址，CPU的累加器数据等，就像我们去开门时要记下我们看的书在第几页了或者干脆作个记号，因为我们待会还要继续接着看后面的书。
CPU总是按照我们的意愿去做应该做的事情，但你错误的给它一件事情，它也会同样的去做，这一点我们必须注意。
中断并不是只有一个，有时会同时存在几个中断，中断具有优先的级别，他们会根据人的要求去执行更高级别的中断。
这种中断中的中断也就形成了中断嵌套。
当然中断的级别根据各种PLC内部CPU的资源有关，同时也跟堆栈的容量大小也有关系。
中断的内容有很多种，比如外部中断、通信中的发送和接受中断、定时和计数的时钟中断、还有WDT复位中断等，它们丰富了CPU在处理各种事务时响应种类。
这样讲也许你并不能完全理解中断的内部结构和操作顺序，我们做一个小小的例子来说明.每一个设备总是不会忘记有一个按钮，它也是在我们遇到紧急情况时使用的，那就是急停按钮。
当我们遇到人身事故和意外情况时我们只要按下它，机器立即停止所有的操作，并等待处理完意外后再恢复操作。
急停按钮连接PLC内部CPU的内部I/O接口上，当按钮给CPU一个外部触发信号时，CPU对I/O进行再次检测，当确认有外部触发信号时，CPU保护现场并将程序计数器自动转到相应的外部I/O中断程序中去，当外部中断程序处理完毕，程序计数器返回到主程序继续工作。
有一点可以说明的是我们一般会把急停按钮的外部中断升至最高级别，从而保证安全。
当我们在工作完一个工件时，给PLC一个信号，将PLC的内部计数器加1来计算我们一天的工作量时，一个简单的计数器能解决问题，当然它们也能够在掉电的情况下保持数据，促使数据不丢失，这也是我们所渴望的。
PLC还具有高级计数器的功能，当我们在接受一些高速的数据时，这里所说的高速是在在微秒级的数据，比如条码扫描机在不断的扫描数据，数据处理器DSP计算的高速信号等，我们就要采用到高级计数器来帮助我们进行计数。
它在PLC执行程序时一旦发现高级计数器对应的中断，就会立即放下手上的工作。
经过再次编程的梯形图程序说明我们在执行程序时高级计数器会自动的执行对应的工作，从而将高级计数器的级别升至高一级别。
你也许听过太多的这个词:“死机”，大致的意思是CPU工作量过大，内部资源不足等情况造成程序无法运行。
PLC也有类似的情况，在PLC内部有一个看门狗WDT，我们可以设置WDT一个程序运行的时间，当程序运行过程中出现程序跳转错误时或者程序繁忙时，程序的运行时间超过WDT的设置时间，CPU转而WDT复位状态。
程序重新开始运行，但对中断不会进行破坏。
PLC的发展已经从单一的模式进入了通信的网络时代，并同其它的工控网板和I/O 卡板轻易的进行共享。
组态软件可以将所有的这些硬件连接起来，通过更直观的动画图片来进行控制，并可以通过互联网在异地进行控制，像神舟五号的发射就是采用这种办法来使飞船升空。
更高层次的发展需要我们不断的努力来取得。
PLC的出现已经足足影响了几代人，我们也从上一辈的经验中获取了更多的知识和教训，来不断的发展PLC技术，将它推向更高浪潮。