外文翻譯---可編程邏輯控制器

1、<p>　　附錄二 外文文獻(xiàn)及其翻譯</p><p>　　Programmable logic controller</p><p>　　Cynthia cooper </p><p>　　From Wikipedia, the free encyclopedia</p><p>　　A programmable logic con

2、troller or simply 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 f

3、or 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

4、or non-volatile memory. A PLC is an </p><p><b>　　Features</b></p><p>　　Control panel with PLC (grey elements in the center). The unit consists of separate elements, from left to righ

5、t; power supply, controller, relay units for input and output.</p><p>　　The main difference from other computers is that PLCs are armored for severe condition (dust, moisture, heat, cold, etc) and have the f

6、acility for extensive input/output (I/O) arrangements. These connect the PLC to sensors and actuators. PLCs read limit switches, analog process variables (such as temperature and pressure), and the positions of complex p

7、ositioning systems. Some even use machine vision. On the actuator side, PLCs operate electric motors, pneumatic or hydraulic cylinders, magnetic </p><p>　　PLCs were invented as replacements for automated sys

8、tems 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 automotiv

9、e manufacturing industry, where software revision replaced the re-wiring of hard-wired control panels when production models changed.</p><p>　　Many of the earliest PLCs expressed all decision making logic in

10、 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

11、 reduce training demands for the existing technicians. Other early PLCs used a form of instruction list programming, based on a stack-based logic solver.</p><p>　　The functionality of the PLC has evolved ove

12、r 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

13、s are approximately equivalent to desktop computers. PLC-like programming combined with remote I/O hardware, allow a general-purpose desktop computer to overlap some PLCs in certain applications.</p><p>　　Un

14、der the IEC 61131-3 standard, PLCs can be programmed using standards-based programming languages. A graphical programming notation called Sequential Function Charts is available on certain programmable controllers.</p

15、><p>　　PLC compared with other control systems</p><p>　　PLCs are well-adapted to a range of automation tasks. These are typically industrial processes in manufacturing where the cost of developing

16、and maintaining the automation system is high relative to the total cost of the automation.PLCs contain input and output devices compatible with industrial pilot devices and controls.PLC applications are typically highly

17、 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 ha</p><p>　　For high volume or very simple fixed automation tasks, dif

18、ferent techniques are used. For example, a consumer dishwasher would be controlled by an electromechanical cam timer costing only a few dollars in production quantities.</p><p>　　A microcontroller-based desi

19、gn would be appropriate where hundreds or thousands of units will be produced and so the development cost (design of power supplies and input/output hardware) can be spread over many sales, and where the end-user would n

20、ot need to alter the control. Automotive applications are an example; millions of units are built each year, and very few end-users alter the programming of these controllers. However, some specialty vehicles such as tra

21、nsit busses economically use PLC</p><p>　　Very complex process control, such as used in the chemical industry, may require algorithms and performance beyond the capability of even high-performance PLCs. Very

22、 high-speed or precision controls may also require customized solutions; for example, aircraft flight controls.</p><p>　　PLCs may include logic for single-variable feedback analog control loop, a "propo

23、rtional, integral, derivative" or "PID controller." A PID loop could be used to control the temperature of a manufacturing process, for example. Historically PLCs were usually configured with only a few an

24、alog control loops; where processes required hundreds or thousands of loops, a distributed control system (DCS) would instead be used. However, as PLCs have become more powerful, the boundary between DCS and PLC ap</p

25、><p>　　Digital and analog signals</p><p>　　Digital or discrete signals behave as binary switches, yielding simply an On or Off signal (1 or 0, True or False, respectively). Push buttons, limit swit

26、ches, and photoelectric sensors are examples of devices providing a discrete signal. Discrete signals are sent using either voltage or current, where a specific range is designated as On and another as Off. For example,

27、a PLC might use 24 V DC I/O, with values above 22 V DC representing On, values below 2VDC representing Off, and intermediate v</p><p>　　Analog signals are like volume controls, with a range of values between

28、 zero and full-scale. These are typically interpreted as integer values (counts) by the PLC, with various ranges of accuracy depending on the device and the number of bits available to store the data. As PLCs typically u

29、se 16-bit signed binary processors, the integer values are limited between -32,768 and +32,767. Pressure, temperature, flow, and weight are often represented by analog signals. Analog signals can use voltage o</p>

30、<p>　　Programming</p><p>　　Early PLCs, up to the mid-1980s, were programmed using proprietary programming panels or special-purpose programming terminals. they were designed to replace relay logic syst

31、ems. These PLCs were programmed in "ladder logic", which strongly resembles a schematic diagram of relay logic. Modern PLCs can be programmed in a variety of ways, from ladder logic to more traditional programm

32、ing languages such as BASIC and C. Another method is State Logic, a Very High Level Programming Language designed to</p><p>　　Recently, the International standard IEC 61131-3 has become popular. IEC 61131-3

33、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, si

34、milar to assembly language) and SFC (Sequential function chart). These techniques emphasize logical organization of operations.</p><p>　　While the fundamental concepts of PLC programming are common to all ma

35、nufacturers, 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 manu

36、facturer, different models may not be directly compatible.</p><p>　　User interface</p><p>　　PLCs may need to interact with people for the purpose of configuration, alarm reporting or everyday co

37、ntrol. A Human-Machine Interface (HMI) is employed for this purpose. HMI's are also referred to as MMI's (Man Machine Interface) and GUI (Graphical User Interface).</p><p>　　A simple system may use b

38、uttons and lights to interact with the user. Text displays are available as well as graphical touch screens. Most modern PLCs can communicate over a network to some other system, such as a computer running a SCADA (Super

39、visory Control And Data Acquisition) system or web browser.</p><p>　　Communications</p><p>　　PLCs usually have built in communications ports usually 9-Pin RS232, and optionally for RS485 and Eth

40、ernet. Modbus or DF1 is usually included as one of the communications protocols. Others' options include various fieldbuses such as DeviceNet or Profibus. </p><p><b>　　History</b></p>

41、<p>　　The PLC was invented in response to the needs of the American automotive industry. Before the PLC, control, sequencing, and safety interlock logic for manufacturing automobiles was accomplished using relays, t

42、imers and dedicated closed-loop controllers. The process for updating such facilities for the yearly model change-over was very time consuming and expensive, as the relay systems needed to be rewired by skilled electrici

43、ans. In 1968 GM Hydramatic (the automatic transmission division of Gene</p><p>　　The winning proposal came from Bedford Associates of Bedford, Massachusetts. The first PLC, designated the 084 because it was

44、Bedford Associates' eighty-fourth project, was the result. Bedford Associates started a new company dedicated to developing, manufacturing, selling, and servicing this new product: Modicon, which stood for MOdular DI

45、gital CONtroller. One of the people who worked on that project was Dick Morley, who is considered to be the "father" of the PLC. The Modicon brand was sold in</p><p>　　The automotive industry is st

46、ill one of the largest users of PLCs, and Modicon still numbers some of its controller models. PLCs are used in many different industries and machines such as packaging and semiconductor machines. Well known PLC brands a

47、re Toshiba, Siemens, Allen-Bradley, ABB, Mitsubishi, Omron, and General Electric.</p><p><b>　　中文譯文：</b></p><p><b>　　可編程邏輯控制器</b></p><p><b>　　辛西婭.庫珀<

48、/b></p><p><b>　　維基自由百科全書</b></p><p>　　可編程邏輯控制器或者簡易可編程控制器是一種數(shù)字化的計算機(jī)，它應(yīng)用于工業(yè)自動化的生產(chǎn)過程中，比如工廠裝配生產(chǎn)線中機(jī)械的控制。不同于普通用途的計算機(jī)，可編程邏輯控制器是專為安排多輸入和多輸出而設(shè)計的，它拓展了工作溫度范圍，可抑制電氣噪聲，抗振動和干擾。程序控制機(jī)器操作指令通常存儲在備用

49、電池或非易失性存儲器中。PLC要求實(shí)時系統(tǒng)的輸出結(jié)果在一個時間范圍內(nèi)必須對輸入條件做出響應(yīng)，否則會導(dǎo)致誤操作。</p><p><b>　　特征</b></p><p>　　PLC的控制面板（灰色元素的中心），它的每個單位都是由單獨(dú)的元素組成的，由左向右分別是：電源供應(yīng)器，控制器，繼電器單元的輸入輸出。</p><p>　　PLC和其他計算機(jī)的

50、主要區(qū)別是它適用于各種惡劣環(huán)境條件（如灰塵，潮濕，高溫，低溫等），并配備了適合于各種輸入/輸出端口的設(shè)備。 這些設(shè)備將PLC連接到相應(yīng)的傳感器和信號發(fā)生器上。PLC可以定義各種開關(guān)量，模擬量（如溫度和壓力等）用來配置各種復(fù)雜系統(tǒng)的各種變量，一些PLC甚至還需要使用機(jī)器視覺。在信號發(fā)生器方面，PLC可以控制的設(shè)備有電動機(jī)，氣壓缸或液壓缸，電磁繼電器或螺線管繼電器，以及一些模擬輸出設(shè)備。通過輸入/輸出模塊的配置，可以構(gòu)建一個簡單的PLC系統(tǒng)

51、。這個PLC系統(tǒng)可以通過外部I/O模塊連接到一個計算機(jī)網(wǎng)絡(luò)上。</p><p>　　PLC的出現(xiàn)改變了過去使用成百上千的繼電器、凸輪定時器、鼓音序器來構(gòu)建一個自動化系統(tǒng)的時代。通常，一個簡單可編程控制器通過編程以取代成千上萬的繼電器。 可編程控制器最初應(yīng)用于汽車制造業(yè)中，軟件修改取代了硬連線控制面板的重新布線，這標(biāo)志著生產(chǎn)模式發(fā)生了徹底的改變。</p><p>　　許多早期的PLC設(shè)計表明

52、，在簡單的梯形邏輯的決策中，已經(jīng)出現(xiàn)了類似梯形圖的電氣原理圖。電工們通過使用梯形邏輯能夠很方便的查找出電路示意圖的問題。這項(xiàng)計劃符號的選擇使用可以降低培訓(xùn)其現(xiàn)有的技術(shù)人員的要求。而其他早期的PLC則使用一種基于堆棧的邏輯解決方法——指令表編程的方式。 </p><p>　　PLC的功能經(jīng)過多年的發(fā)展，已經(jīng)包括順序控制，運(yùn)動控制，過程控制，分布式控制系統(tǒng)和網(wǎng)絡(luò)控制系統(tǒng)等多個方面。一些現(xiàn)代的PLC的數(shù)據(jù)處理、儲存、整

53、理和通信能力已大約相當(dāng)于臺式電腦了?？删幊炭刂破鞯木幊探Y(jié)合遠(yuǎn)程I/O硬件，允許通用臺式電腦進(jìn)行一些PLC方面的特定應(yīng)用。</p><p>　　根據(jù)國際電工委員會61131-3標(biāo)準(zhǔn)，PLC的編程可以使用基于標(biāo)準(zhǔn)的編程語言。所謂順序功能圖的圖形符號編程適用于某些特定的可編程控制器。</p><p>　　可編程控制器與其他控制系統(tǒng)</p><p>　　PLC可以很好的適應(yīng)

54、各種自動化任務(wù)。這些都是典型的工業(yè)機(jī)械生產(chǎn)，這些部門自動控制系統(tǒng)的高額費(fèi)用是與其昂貴的的制造維護(hù)費(fèi)用分不開的。PLC能控制輸入輸出設(shè)備并兼容工業(yè)試驗(yàn)裝置和控制。通常PLC應(yīng)用于高度定制的系統(tǒng),以便使組裝PLC的成本低于設(shè)計控制器的成本。另外，在大規(guī)模生產(chǎn)產(chǎn)品方面，自定義的控制系統(tǒng)是經(jīng)濟(jì)的，由于他的組成部分成本較低。這是代替通用解決方案的最佳選擇。</p><p>　　為大批量或者簡單的固定自動化任務(wù)，不同的技術(shù)被

55、采用。例如：消費(fèi)者洗碗機(jī)被成本只有幾美元的機(jī)電凸輪計時器控制。</p><p>　　微處理器的設(shè)計要考慮成百上千的組成單元，以便開發(fā)成本（電源供應(yīng)器和輸入輸出硬件的設(shè)計）能遍布到很多銷售領(lǐng)域，并且最終用戶不需要改變控制。汽車應(yīng)用是一個例子，每年有數(shù)以百萬輛汽車被制造，只有極少數(shù)最終用戶改變控制程序。然而，一些特殊車輛，如使用PLC系統(tǒng)代替定制設(shè)計控制的過境巴士因?yàn)槭褂昧可偎蚤_發(fā)費(fèi)用不夠經(jīng)濟(jì)。</p>

56、<p>　　復(fù)雜的過程控制，如用于化學(xué)工業(yè)的過程控制要求的算法和性能甚至超過了高性能的PLC控制。高速度和精度的控制也可能需要量身定制的解決方案，如飛機(jī)的飛行控制。</p><p>　　PLC系統(tǒng)包括邏輯單變量反饋模擬控制回路，一個“比例、積分、導(dǎo)數(shù)”或“控制器”。PID回路可用于控制制造過程的溫度，例如歷史上的PLC通常只用于少數(shù)模擬控制回路這個過程需要成百上千的循環(huán)、分布式控制系統(tǒng)（DCS）將代

57、替使用。然而，由于PLC的功能越來越強(qiáng)大，DCS與PLC的界定越發(fā)的不明確。</p><p><b>　　數(shù)字和模擬信號</b></p><p>　　數(shù)字或離散信號表現(xiàn)為二進(jìn)制開關(guān)信號，收益率只是一個閉合或關(guān)斷信號。按鈕、限位開關(guān)、光電傳感器能提供了一個離散信號。離散信號以電壓或電流的形式傳送，它在一個特定的范圍內(nèi)被設(shè)置成開和關(guān)。例如：PLC必須使用24伏直流電壓的I

58、/O口，高于22伏直流電壓代表開，低于2伏直流電壓代表關(guān)，中間值不確定。最初，PLC只有離散的I/O接口。</p><p>　　模擬信號和音量控制一樣，在零和滿量程之間有一系列的值。這些常常被定義為PLC中的整數(shù)，它的范圍取決于設(shè)備中可用來存儲比特數(shù)據(jù)的存儲單元的數(shù)量。由于PLC通常使用16位有符號二進(jìn)制處理器，整數(shù)值被限定在-32768—+32767之間。壓力、溫度、流量、重量往往代表的模擬信號。模擬型號可以使

59、用與原信號成正比的電壓或電流信號。例如：一個4-20mA的電流信號或者0-10V的電壓信號將被轉(zhuǎn)化成一個0-32767之間的整型值。</p><p><b>　　編程</b></p><p>　　早期的PLC（直至20世紀(jì)80年代中期）使用專有的編程渠道或特殊用途的編程終端進(jìn)行編程。它們是用來取代繼電器邏輯系統(tǒng)的。這些PLC用梯形圖編程，其非常類似于繼電器邏輯示意圖。

60、現(xiàn)代的PLC可以以各種方式編程，從梯形圖到更傳統(tǒng)的編程語言，如BASIC和C，另一種高級程序設(shè)計語言是State Logic，它是基于狀態(tài)轉(zhuǎn)移圖設(shè)計PLC程序的。</p><p>　　最近，國際標(biāo)準(zhǔn)IEC61131-3已經(jīng)流行。目前的IEC61131-3為可編程控制系統(tǒng)定義了5編程語言：FBD（功能框圖），LD（梯形圖），ST（結(jié)構(gòu)化文本），IL（指示表）和SFC（順序功能圖）。這些技術(shù)強(qiáng)調(diào)動作的邏輯組織。 &l

61、t;/p><p>　　所有制造商PLC編程的基本概念是共同的，分歧在于I/O的選擇，存儲組織的安排和指令集，所以不同生產(chǎn)商之間的PLC程序從來都不可以完全的互換。即使是同一制造商同一產(chǎn)品線，不同的模式也可能無法兼容。</p><p><b>　　用戶界面</b></p><p>　　PLC為了配置，報警或日?？刂频哪康目赡苄枰藱C(jī)互動交流。HMI（

62、人機(jī)界面）因此而產(chǎn)生。人機(jī)界面包括MMI（人機(jī)接口）和GUI（圖形用戶界面）。</p><p>　　一個簡單的系統(tǒng)可以使用按鈕和燈來與用戶互動。文字顯示以及圖形化的觸摸屏也可能用到。最現(xiàn)代的PLC可以通過網(wǎng)絡(luò)連接到其他的系統(tǒng)，如運(yùn)行SCADA（監(jiān)控和數(shù)據(jù)采集系統(tǒng)）的計算機(jī)系統(tǒng)或網(wǎng)絡(luò)瀏覽器。</p><p><b>　　通信</b></p><p&g

63、t;　　PLC的內(nèi)置通信端口通常使用9針的RS232串口 ，并選擇性使用RS485的和以太網(wǎng)。Modbus協(xié)議或DF1是常用的一種通信協(xié)議。其他通信協(xié)議包括各種現(xiàn)場總線，如DeviceNet現(xiàn)場總線或Profibus現(xiàn)場總線等。</p><p><b>　　歷史</b></p><p>　　PLC是應(yīng)美國汽車業(yè)發(fā)展的需要而產(chǎn)生的。在PLC產(chǎn)生之前，汽車使用繼電器進(jìn)行順

64、序控制和安全聯(lián)鎖邏輯，制造定時器和專用閉環(huán)控制器。每年模型轉(zhuǎn)換是非常耗時和昂貴的，而且中繼系統(tǒng)需要有熟練的電工才能操作。在1968年通用汽車公司發(fā)出一份為硬連線中繼系統(tǒng)尋找一個電子替代品的建議書。</p><p>　　中標(biāo)投標(biāo)書來自貝德福德，馬薩諸塞州的貝德福德聯(lián)營公司。第一個PLC，被命名為084 ，因?yàn)樗秦惖赂５碌牡诎耸膫€項(xiàng)目的結(jié)果。貝德福德聯(lián)營協(xié)會創(chuàng)建了一個新的公司，它致力于開發(fā)，制造，銷售和服務(wù)這一新

65、產(chǎn)品：莫迪康，它代表模塊化數(shù)字控制器。該項(xiàng)目主持者切尼莫雷，被認(rèn)為是“PLC之父”。該莫迪康品牌在1977年被古爾德電子收購，后來又被德國AEG公司收購，然后是法國施耐德電氣，也是目前的所有者。</p><p>　　汽車行業(yè)仍然是最大的一個PLC用戶，莫迪康仍然標(biāo)稱一些控制器的模型。PLC應(yīng)用在許多不同的行業(yè)和機(jī)器上，如包裝機(jī)和半導(dǎo)體設(shè)備。眾所周知，PLC的品牌有東芝，西門子，艾倫布拉德利，ABB，三菱，歐姆龍和