外文翻译--可设计的逻辑控制器.docx

programmable logic controllera programmable logic controller (plc) or programmable controller is a digital computer used for automation of industrial processes, such as control of machinery on factory assembly lines. unlike general-purpose computers, the plc is designed for multiple inputs and output arrangements, extended temperature ranges, immunity to electrical noise, and resistance to vibration and impact. programs to control machine operation 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 response to input conditions within a bounded time, otherwise unintended operation will result. plc and programmable logic controller are registered trademarks of the allen-bradley company, although they are widely used generically.features the main difference from other computers is that plc are armored for severe condition (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), and the positions of complex positioning systems. some even use machine vision. on the actuator side, p l c operates electric motors, pneumatic or hydraulic cylinders, magnetic relays or solenoids, or analog outputs. the input/output arrangements 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. p l c was invented as replacements for automated systems that would use hundreds or thousands of relays, cam timers, and drum sequencers. often, a single plc can be programmed to replace thousands of relays. programmable controllers were initially adopted by the automotive manufacturing industry, where software revision replaced the re-wiring of hard-wired control panels when production models changed. many of the earliest plc expressed all decision making logic in simple ladder logic which appeared similar to electrical schematic diagrams. the electricians were quite able to trace out circuit problems with schematic diagrams using ladder logic. this program notation was chosen to reduce training demands for the existing technicians. other early plc used a form of instruction list programming, based on a stack-based logic solver. the functionality of the plc has evolved over the years to include sequential relay control, motion control, process control, distributed control systems and networking. the data handling, storage, processing power and communication capabilities of some modern plc are approximately equivalent to desktop computers. plc-like programming combined with remote i/o hardware, allow a general-purpose desktop computer to overlap some plc in certain applications. under the iec 61131-3 standard, plc can be programmed using standards-based programming languages. a graphical programming notation called sequential function charts is available on certain programmable controllers.60s in last century, because of american car industry need to carry on large-scale technique reformation and equipments to renew, from traditionally control equip to carry on a control after the electric appliances, not only the physical volume be huge, breakdown rate, gentle bad, ineffective live, consume ability, and adjust to try difficulty, the credibility is also bad.1968the year american g.m. company puts forward using conceive of new generation controller, consider from the customers angle and that company lifted to request at 10:00 to the new generation controller and provided an explicit development target for each archduke department. next year, from the american dec (numerical equipments company) developed to succeed first the first set programmable logic controller pdp-14.about in the meantime the american modicon company also develops 084 controllers. they publish, caused focus attention of whole world, other companies and western europe in the united states, japanese the etc. industry be flourishing nation, also study to develop a product for is similar to one after another.the plc absorbs micro-electronics technique and the calculator technical last word, so develop to quickly automate the whole automation of production line from the single machine very, is go to produce of the whole factory automation, from gentle manufacturing system, industrial robot arrive the large dispersion type control system and the plc all undertakes to emphasize an important person color.the plc technique represented nowadays electricity procedure to control of earliest enter level. equip (like intelligence appearance, numeral turn handbill device, intelligence of the liquid press to compatibly move a valve set etc.) with various unit automation through a plc and the spot total line, calculator network system, constitute car and factory automate of complete system.usually adopt in the in proper order control realm of industrial control before the plc invent such as take a reading machine after the electric appliances, drum type switch, paper etc. machine, electricity type the spare part is to control a component, particularly is control after the electric appliances, become the spare part that use most extensively in switch control system in long lost the manufacturing the process the control the realm. but, along with the development of industry modernization, production scale more and more big, labor rate of production and product quality of the request is continuously raising, for control system of the credibility also put forward higher request, originally possessed after electric appliances control system already unwell should need, investigate its reason be: the action is slow-moving; the life span is short and the credibility be bad; the physical volume is big, consume an electricity have another; design a manufacturing a period long, procedure modification time-consuming; fall through to have a conversation with calculator. expect behind till 60s in last century, although the small scaled calculator has been gradually perfect and apply realm is also continuously extending, the small scaled calculator used for switch control system, obviously exist the circumstance of malaysia pull a small car again, this is because the characteristics of small scaled calculator decide: the plait distance woven distance complications, requested to have higher level personnel and operate a personnel; need the kit not- standard exterior connects and conditionally once requested to the environment and the spot; function excess, the machine resources can not well make use of; build price high. need and possibility, urge people to look for new exit, the plc emerge with the tide of the times. it is apply in the car industry in the united states first, the plc that is at this time uses solid(integration) electric circuit to replace electric circuit after the electric appliances logic and use saving machine electric circuit in of saving digital(procedure) replace after the cloth line of electric appliances system, rule a logic relation with the procedure; use the solid i/ o electric circuit to examine the signal of button and limit switch, carry out organization by the control electrical engineering and the other for an exportation. the plc system that is at this time has already started have as follows some characteristics: the environment adaptability is stronger, can be use in a car the spot; there is higher credibility and diagnosis ability, maintain easily; basic can adapt different manufacturing process need, the gentle degree more and greatly raised, want only the procedure in the change system namely convertibility a control logic, but didnt need to be reform or didnt replace control hardware.since 1976, the microprocessor starts lead into the plc realm, consumedly strengthen a plc function and make plc from in brief replace after the electric appliances electric circuit, but develop to equip into the control which enters first. the plc has to collect and handles a great deal of data, completion mathematics operation and correspond by letter with other intelligence spare parts nowadays of ability, and have the forerunners person machine to the words means(if keyboard, crt and speech have a conversation), in recent years because of the spot emergence and related standard establishment of total line principle, and the quick development of product, the plc become the spot total line of an importance constitute part, extended plc applied realm further. because the plc raised function with gentle degree in the meantime, make its application quickly increase, and make widely available many other long-lost spare parts manufacture industry realm. later on again expand to and criticize quantity to produce with continuous production line relevant of industrial realm. along with the cims (calculator integration manufacturing system) development, the plc is still used for factory by people to correspond by letter a network at present in, become a calculator with other intelligence controllers and calculator system together comprehensive control system in of importance constitute part, especially unit class and work station class. from 1969 the first set p l c publish up to now and the programmable controller about experienced three stages: first stage: the plc capacity of the development is smaller, i/o the point be small at 120:00.the customer saves area capacity or so scan the speed as 2050 ms k b in the 2 kb s, the instruction is more simple and only have logic an operation and account, count etc., weave distance language to adopt a simple language sentence a predicative speech. mainly use to make amount of switch a control on the usage. second stage: the plc capacity has to expand, the i/o point is from 512-1024:00, customers procedure saves area to expand to 8 k b s above, the speed also has an exaltation, scan speed to attain a 56 ms k b, instruction function in addition to the basic logic operate, accounts, count, also increased an arithmetic operation instruction and compare instruction, and imitate a quantity processing instruction etc., input/output type also from pure switch quantity i/o, expand for the i/o which takes emulation quantity. weave distance language in addition to using a language sentence form, can also use the trapezoid diagram plait distance language.the third stage: get into 80s, along with large-scale and super micro-electronics technical fast fierce development of large scale integration etc., the plc constituted by 16 and 32 microprocessors gets an astonishing development and its function far and far outran above-mentioned product of two stages. make the plc design in the concept, the sex price ratio and applied all had new breakthrough. the product of this stage developed toward two large and small scaled directions. the i/o of the large product point, over 4000:00ses, some products attain 8000 i/os to order, customer saving the area capacity install various intelligence mold piece(for example temperature control mold piece, stalk fixed position mold piece, process control mold piece etc.) and correspond by letter a mold piece over the 32 k b s and scan the velocity also consumedly raise, attain a 0.47 ms kb, instruction function in addition to basic logic operation, account, count, in proper order control, also have arithmetic to float to order operation instruction, pid to regulate the tai function instruction, network of the function instruction, sketch set and correspond by letter instruction.etc. weave distance language widespread trapezoid language, also use a language sentence the preface function diagram language with amiable form in the meantime.(typical model of have grafcet language)considered permitting wrong technique and redundancy technique etc. in the design for the sake of the credibility of the exaltation system. the small scaled product of this stage to super and small scaled turn and strengthen a function development, there is 16:00 i/o, at 24:00 the whole type of the i/o small scaled plc the allocation imitates quantity i/o, correspondence on the small scaled plc, high speed count, also establish an arithmetic operation on the instruction, compare instruction and pid regulate instruction. the hand hold type plait distance machine that the small scaled plc use uses big area liquid crystal display can also be with trapezoid diagram and grafcet language carry on weaving a distance. the software design of this stage plc also includes to very greatly improve, widespread carried out a software mold a piece to turn a design, provide on the plc product in great quantities in general use with the appropriation software function mold piece, the customer adjust to use through a simple function and then can carry out complicated control mission to bring usage tremendous convenience. the plait distance of the usage the machine be more and more perfect, the appropriation plait distance machine is actually already a personal calculator, can carry out an off-line plait distance or on-line plait distance and supervision, the procedure print and the procedure be solid to turn, carry out sketch set tai, can unite a net(namely hang on the plc network), some plait distance machines can also use deluxe language this help that brought plc further development very, also make plc application more extensive.可设计的逻辑控制器一个可设计的逻辑控制器 (plc), 或可设计的控制器是对自动化是二手的一部数传计算机工业的程序, 像是控制机器在工厂装配线上。 不像泛用型的计算机, plc 是设计为倍数输入和输出安排, 广大的温差, 免疫到电的噪音, 和对震动的抗拒和冲击。 计画到控制机器操作典型地储存在电池中-支持或非挥发性记忆。 plc 是例子一真正的时间系统自从输出结果一定是生产回应输入情况在一里面跳跃时间, 另外不有意的操作意志结果。plc 和可设计的逻辑控制器是艾伦-布拉德利公司的注册的商标, 虽然他们广泛地二手的关于属类。 特征主要的不同从其他的计算机是 plc 对严格的情况 (灰尘, 湿气, 热, 寒冷, 及其他) 是披甲的和有设备为广泛的输入/输出 (输入输出) 安排。 这些把 plc 连结到感应器和主动器。 plcs 阅读界限开关, 类比程序变数 (像是温度和压力), 和那位置合成物定位系统。 一些甚至使用机器视觉。 在主动器上边, plcs 操作电的马达, 空气的或水力的圆筒, 磁性接替者或螺线形电导管, 或类比输出。 那输入/输出安排可能是进入简单的 plc 之内建造, 或 plc 可能有外部的输入输出组件附件对一个计算机网络哪一塞子进入 plc 之内。 plcs 是发明当做替换因为自动化系统哪一会使用数百或数以千计的接替者, 凸轮定时器, 和鼓顺序器。 时常, plc 能是规划代替数以千计的接替者。可设计的控制器最初是被收养的被汽车制造工业, 哪里软件代替的校订那再配线难-以线加强的控制嵌板当生产模型改变。表达的大部份最早的 plcs 所有的在简单的梯逻辑中的决策逻辑出现相似的对电概要的图表。电学家出自线路对痕迹相当能够，使用的概要图表的问题袜子抽丝逻辑。 这一个计画记号法被选择减少训练要求为那现有的技术人员。 其他的早 plcs 二手的一形式指导目录规画, 基于一个以堆叠为基础的逻辑解决者。 plc 的功能性有进展年以来包括继续的接替者控制, 运动控制, 程序控制, 分配控制系统而且网络。 数据处理，储藏、处理力量和沟通一些现代的 plcs 的能力大约同等物对桌面计算机。和遥远的输入输出硬件结合的像 plc 一样的规画,让一部泛用型的桌面计算机至在特定的申请中的重叠一些 plcs 。 在 iec 61131-3 标准之下， plcs 能是规划使用以标准为基础的规画语言。 一个图解式的规画记号法呼叫继续的功能图解从特定的可设计的控制器可得。上世纪60年代，由于美国汽车工业需要进行大规模的技术改造和设备更新，由传统的继电器控制装置来进行控制，不仅体积庞大、故障率高、柔性差、不灵活、耗能，而且调试困难，可靠性也差。1968年美国通用汽车公司提出使用新一代控制器的设想，从用户的角度考虑，该公司对新一代控制器提了10点要求，为各大公司提供了明确的开发目标。次年，就由美国dec（数字设备公司）首先研制成功了第一台可编程逻辑控制器pdp-14。差不多同时，美国modicon公司也研制出084控制器。它们的问世，引起了全世界的瞩目，美国的其他公司和西欧、日本等工业发达国家，也相继研究开发出类似的产品。由于plc吸取微电子技术和计算机技术的最新成果，因此发展十分迅速，从单机自动化到整条生产线的自动化，乃至整个工厂的生产自动化，从柔性制造系统、工业机器人到大型分散型控制系统，plc均承担着重要角色。plc技术代表了当今电气程序控制的最先进水平。通过plc与各种单元自动化装置（如智能仪表、数字化传单装置、智能的液压和气动阀组等）以及现场总线、计算机网络系统，构成了车间和工厂自动化的完整体系。在plc发明之前，在工业控制的顺序控制领域内，常常采用诸如继电器、鼓式开关、纸带阅读器等机械、电气式器件作为控制元件，尤其是控制继电器，在离散制造过程控制领域内，成为“开关控制系统”中最广泛使用的器件。但是，随着工业现代化的发展，生产规模越来越大，劳动生产率及产品质量的要求在不断提高，对于控制系统的可靠性也提出了更高的要求，原有“继电器控制系统”已不适应需要，究其原因是： 动作缓慢；寿命短、可靠性差；体积大、耗电多；设计制造周期长、程序修改费时；不能实现与计算机对话。到上世纪60年代后期，虽然小型计算机已日趋完善，应用领域也在不断扩大，但小型计算机用于开关控制系统，又显然存在着“大马拉小车”的情况，这是由于小型计算机的特点决定的：编程复杂，要求有较高水平的编程人员和操作人员； 需要配套非标准的外部接口，对环境和现场条件的要求过高； 功能过剩