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1、<p><b>  晉 中 學(xué) 院</b></p><p>  本科畢業(yè)設(shè)計(jì)英文參考資料</p><p>  題 目 Programmable Logic </p><p>  Controller PLC </p><p>  院 系 機(jī)械學(xué)院

2、 </p><p>  專 業(yè) 機(jī)械設(shè)計(jì)制造及其自動(dòng)化 </p><p>  姓 名 黨佳明 </p><p>  學(xué) 號(hào) 1014312109 </p><p>  學(xué)習(xí)年限2010年09月至2012年07月 </p&g

3、t;<p>  指導(dǎo)教師 王麗珍 職稱 講師 </p><p>  申請(qǐng)學(xué)位 工學(xué) 學(xué)士學(xué)位 </p><p>  2012年05月20日</p><p><b>  英文原文:</b></p><p>  Programmable Logic Contro

4、ller PLC</p><p>  1 PLC Introduce</p><p>  PLC Introduction Programmable controller is the first in the late 1960s in the United States, then called PLC programmable logic controller (Programmab

5、le Logic Controller) is used to replace relays. For the implementation of the logical judgment, timing, sequence number, and other control functions. The concept is presented PLC General Motors Coroperation.PLC and the b

6、asic design is the computer functional improvements, flexible, generic and other advantages and relay control system simple and e</p><p> ?、賖igh reliability, anti-interference capability; </p><p&g

7、t; ?、趐rogramming visual, simple; </p><p> ?、?adaptability good;</p><p> ?、?functional improvements, strong functional interface.</p><p>  Programmable Logic Controllers (PLC), a com

8、puting device invented by Richard E. Morley, have been widely used in industry including manufacturing systems, transportation systems, chemical process facilities, and many others. At that time, the PLC replaced the har

9、dwired logic with soft-wired logic or so-called relay ladder logic (RLL), a programming language visually resembling the hardwired logic, and reduced thereby the configuration time from 6 months down to 6 days. </p>

10、;<p>  Although PC based control has started to come into place, PLC based control will remain the technique to which the majority of industrial applications will adhere due to its higher performance, lower price,

11、 and superior reliability in harsh environments. Moreover, according to a study on the PLC market of Frost and Sullivan, an increase of the annual sales volume to 15 million PLC per year with the hardware value of more t

12、han 8 billion US dollars has been predicted, though the prices of computin</p><p>  Though PLC are widely used in industrial practice, the programming of PLC based control systems is still very much relying

13、on trial-and-error. Alike software engineering, PLC software design is facing the software dilemma or crisis in a similar way. Morley himself emphasized this aspect most forcefully by indicating: “If houses were built li

14、ke software projects, a single woodpecker could destroy civilization.” </p><p>  Particularly, practical problems in PLC programming are to eliminate software bugs and to reduce the maintenance costs of old

15、ladder logic programs. Though the hardware costs of PLC are dropping continuously, reducing the scan time of the ladder logic is still an issue in industry so that low-cost PLC can be used. </p><p>  In gen

16、eral, the productivity in generating PLC is far behind compared to other domains, for instance, VLSI design, where efficient computer aided design tools are in practice. Existent software engineering methodologies are no

17、t necessarily applicable to the PLC based software design because PLC-programming requires a simultaneous consideration of hardware and software. The software design becomes, thereby, more and more the major cost driver.

18、 In many industrial design projects, more than 50% of </p><p>  In addition, current PLC based control systems are not properly designed to support the growing demand for flexibility and reconfigure ability

19、of manufacturing systems.</p><p>  PLC is well-adapted to a range of automation tasks. These are typically industrial processes in manufacturing where the cost of developing and maintaining the automation sy

20、stem is high relative to the total cost of the automation, and where changes to the system would be expected during its operational life. PLC contains input and output devices compatible with industrial pilot devices and

21、 controls; little electrical design is required, and the design problem centers on expressing the desired se</p><p>  For high volume or very simple fixed automation tasks, different techniques are used. For

22、 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 design would be appropriate where h

23、undreds or thousands of units will be produced and so the development cost (design of power supplies, input/output hardware and necessary testing and certification) can be spread over many sales, and where the end-user w

24、ould not 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

25、a</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 PLC. Very high-speed or precision control

26、s may also require customized solutions; for example, aircraft flight controls.</p><p>  Programmable controllers are widely used in motion control, positioning control and torque control. Some manufacturers

27、 produce motion control units to be integrated with PLC so that G-code (involving a CNC machine) can be used to instruct machine movements.</p><p>  PLC may include logic for single-variable feedback analog

28、control loop, a "proportional, integral, derivative" or "PID controller". A PID loop could be used to control the temperature of a manufacturing process, for example. Historically PLC was usually conf

29、igured with only a few analog control loops; where processes required hundreds or thousands of loops, a distributed control system (DCS) would instead be used. As PLC has become more powerful, the boundary between DCS an

30、d PLC applications has</p><p>  PLC has similar functionality as Remote Terminal Units. An RTU, however, usually does not support control algorithms or control loops. As hardware rapidly becomes more powerfu

31、l and cheaper, RTU, PLC and DCS are increasingly beginning to overlap in responsibilities, and many vendors sell RTU with PLC-like features and vice versa. The industry has standardized on the IEC 61131-3 functional bloc

32、k language for creating programs to run on RTU and PLC, although nearly all vendors also offer proprietar</p><p>  2 The structure of PLC system</p><p>  Structurally divides, PLC divides into t

33、he stationary type and the combined type (module type) two kinds. Stationary PLC including the CPU board, the I/O board, demonstrated the kneading board, the memory block, the power source and so on; these elements combi

34、ne not a dismountable whole. Module type PLC including the CPU module, the I/O module, the memory, the power source module, the ledger wall or the rack, these modules may defer to certain rule combination disposition.<

35、;/p><p>  1、CPU constitution</p><p>  CPU is the PLC core, plays nerve center's role, wraps PLC to have CPU at least every time, it the function which entrusts with according to the PLC system

36、program receives and stores the user program and the data, with scanning way gathering the condition or the data which sends by the scene input device, coexisting enters the stipulation in the register, simultaneously, d

37、iagnoses the power source and in the PLC internal circuit active status and the programming process grammatical error and so </p><p>  CPU mainly by the operator, controller, register and implementation of d

38、ata link between them, control and state BUS, CPU unit also includes peripheral chips, bus interface and related circuitry. Memory is mainly used for storing programs and data, is an integral unit PLC. </p><p&

39、gt;  In the user view, unnecessarily detailed analysis of the CPU's internal circuitry, but the working mechanism of the various parts, or should have sufficient understanding. CPU and the control work, which will re

40、ad the instructions, directives and executive orders to explain. However, the pace of work from the vibration signals. Computing devices used for digital or logic operation, under the command of the controller work. <

41、;/p><p>  CPU speed and memory capacity are important parameters for PLC, which determines the pace of work PLC, I/O number and software capacity, etc., thereby limiting the control of the scale.</p><

42、;p>  2、I/O modules</p><p>  PLC interface with the electrical circuit is through the input and output section (I/O) completion. I/O module integrates the PLC's I/O circuits; the input register reflect

43、ing the input signal status, output point reflects the state of the output latch. Input module will transform electrical signals into digital signals into the PLC system, the output module opposite. I/O into digital inpu

44、t (DI), digital outputs (DO), analog input (AI), analog output (AO) modules.</p><p>  3、Common I/O as follow</p><p>  Switching capacity: voltage level by points, with 220VAC, 110VAC, 24VDC, by

45、Way of isolation, there is isolation and transistor isolation relays.</p><p>  Analog: by type of signal, a current type (4-20mA ,0-20mA), voltage (0-10V ,0-5V,-10-10V) and so on, by the precision points are

46、 12bit, 14bit, 16bit, etc. .</p><p>  In addition to these general-purpose IO, there are special IO modules, such as thermal resistance, thermocouple, pulse and other modules.</p><p>  By I/O mo

47、dule specifications and to determine the number of points, I/O modules can be more or less, but the maximum number of CPU can be the basic configuration management capabilities, which by the largest floor or rack slot li

48、mit.</p><p>  Power Modules</p><p>  PLC power supply modules for the PLC to provide the power supply integrated circuits. Meanwhile, some of them for the work input circuit to provide 24V power

49、 supply. Power input types are: AC power (220VAC or 110VAC), DC power supply (commonly used to 24VDC).</p><p>  Most modular PLC to use floor or rack, its role is to: electrical, the realization of the modul

50、es, so that the CPU can access all the modules on the floor, machinery and realize the connection between each module, so that each module constitutes a overall.</p><p>  3 Installation and debugging Of PLC

51、control system </p><p>  Programming device: development and application programmer is the PLC to monitor the operation, inspection, maintenance indispensable device for programming, some system settings, mo

52、nitor the PLC and the PLC control system working conditions, but it is not directly involved in field control run. PLC programmers are generally small hand-held programmer, the current general by the computer (running pr

53、ogramming software) as programmer. That is, our system PC.</p><p>  Human Machine Interface is the simplest indicators and buttons, the current LCD screen (or touch screen) type-one operator terminal has bee

54、n widely applied by the computer (running the configuration software) as a very popular man-machine interface.</p><p>  PLC communication network rely on advanced industrial network technology can quickly an

55、d efficiently collect, transfer of production and management of data. Therefore, the network automation system integration projects in the importance of more and more significant, even been suggested that the network is

56、the controller's point of view argument.</p><p>  PLC is a service specifically for the industrial production control device, usually do not need to take measures, it can be directly used in industrial e

57、nvironments. However, when the production environment is too harsh, especially strong electromagnetic interference, or improper installation, can not guarantee the normal operation of PLC, and therefore should pay attent

58、ion to the following questions using the.</p><p>  First, the working environment</p><p>  1. PLC required temperature in the temperature 0 ~ 55 ℃, heating installation, large components can not

59、 be placed below the space around the ventilation and cooling should be large enough, the basic unit and expansion unit interval between the need for more than 30mm; switch cabinet, the lower should be a ventilation shut

60、ters, to prevent too much direct sunlight; if the surrounding Stresses above 55 ℃, to install electric fan forced ventilation.</p><p>  2. PLC humidity in order to ensure the insulation performance, air rela

61、tive humidity should be less than 85% (no condensation).</p><p>  3. PLC should be made from a strong shock vibration source, to prevent the vibration frequency of 10 ~ 55Hz frequent or continuous vibration.

62、 When the environment is inevitable when using vibration, shock absorption to take measures, such as glue, such as using shock absorption.</p><p>  4. Air to avoid corrosion and flammable gases, such as hydr

63、ogen chloride, hydrogen sulfide, etc.. The more the air of dust or corrosive gas environment can be installed in a closed PLC good control room or control cabinet, and install air cleaning devices.</p><p>  

64、5. Power PLC power supply is 50Hz, 220 (1 ± 10%) V AC, for the power cord to the interference, PLC itself has sufficient capacity to resist. Reliability requirements for high power interference is particularly serio

65、us situation or environment, you can install a shield with variable ratio of 1:1 isolation transformer to reduce the interference between the equipment and land. Power input can also be cascaded LC filter circuit</p&g

66、t;<p>  Second, installation and wiring</p><p>  1. Power lines, control lines and power lines and PLC I/O lines should be split wiring, isolation transformer and PLC and I/O should be used between th

67、e cable connections.</p><p>  2. PLC should stay away from strong interference sources such as welding, high-power silicon rectifier devices and large power equipment, not with the high-voltage electrical sw

68、itch installed in the same cabinet.</p><p>  3. PLC input and output separately from the best alignment, switch and analog should be laid separately. The transmission of analog signals should be shielded cab

69、le, one end or both ends of the shield should be grounding resistance should be less than the shielding layer 1 / 10.</p><p>  4. PLC basic unit and expansion modules and functional modules, connecting cable

70、s should be installed separately, to prevent interference from outside signals.</p><p>  5. AC output line and DC output lines do not use the same cable, the output line should be far from power lines and po

71、wer lines, to avoid parallel.</p><p>  Third, I/O wiring terminal</p><p>  1. Input Connection</p><p>  (1) Input connection generally should not exceed 30 meters. But if the enviro

72、nment interfere with small, small voltage drop, the input terminal</p><p>  Longer be appropriate.</p><p>  (2) Input / output lines can not be used with a cable, input / output lines should be

73、separated.</p><p>  (3) The extent possible, normally open contact form connected to the input in the establishment of the ladder and relay the same schematic</p><p>  2. Output connection</p

74、><p>  (1) Output terminal is divided into separate output and public output. In different groups, using different types and voltage levels of output voltage. However, output in the same group can only use the

75、same type, the same voltage level of power.</p><p>  (2) Since the PLC's output devices are packaged in printed circuit board and connected to the terminal board that if the load short-circuits connectin

76、g the output components, printed circuit boards will be burned, thus, applied fuse protected output devices.</p><p>  (3) The relay output, inductive load borne by the size, will affect the life of the relay

77、, therefore, choose to use the relay inductive load longer working life.</p><p>  (4) PLC may interfere with the output load, so to take measures to control, such as the DC output of the continued flow of co

78、ntrol protection, exchange of the output RC snubbed circuit, transistors and resistors Triad output bypass the protection.</p><p>  Third, the external safety circuit</p><p>  In order to ensure

79、 that the entire system to work reliably in a safe condition to avoid failure due to external power supply, PLC abnormalities, misuse, and the output error caused major economic losses and human casualties, PLC necessary

80、 protection should be installed outside the circuit.</p><p>  (1) Emergency stop circuit. The user can load the risk of harm, in addition to be taken into account in the control program, it should design ext

81、ernal emergency stop circuit, PLC failure, the load can cause injury and reliable power supply cut off.</p><p>  (2) Protection circuit. Reversible operation such as forward and reverse operation of the cont

82、rol system, to set an external electrical interlock protection; reciprocating and down movement of the control system, to set the outer limit protection circuits.</p><p>  (3) Programmable controller self-te

83、st features such as watchdog timer check out the unusual, the output all closed. But when the PLC CPU can not control when the output fault, therefore, can damage the danger of the user load, to ensure that the equipment

84、 in a safe condition to run, need to design the external circuit to be protective.</p><p>  (4) Power supply overload protection. If the PLC power supply failure, interruption time of less than 10 seconds, P

85、LC work will not be affected, if the power failure or power down more than 10 seconds exceeded allowable value, then the PLC to stop working, all the output points are also broken; when power restored If the RUN input co

86、nnected, the operation automatically. Therefore, some easy to overload the input device should be set to the necessary limit protection circuits.</p><p>  (5) Major fault alarm and protection. Major accident

87、-prone places, in order to ensure that the control system in a major accident is still reliable alarm and protection,should be associated with major fault signal output through the external circuit to the control system

88、to run in the security situation.</p><p>  4 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

89、, respectively). Push buttons, limit switches, and photoelectric sensors are examples of devices providing a discrete signal. Discrete signals are sent using voltage or current, where a specific range is designated as on

90、 and another as off. For example, a PLC might use 24 V DC I/O, with values above 22 V DC representing on, values below 2VDC representing off, and intermediate values u</p><p>  Analog signals are like volume

91、 controls, with a range of values between 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 availab

92、le to store the data. As PLC typically use 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. Ana

93、log signals can use voltage or</p><p>  Atonally, along with the development of the ages, the people see in produce practice, automate brought the tremendous convenience and the product quantities for people

94、 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 b

95、est decision etc., well-trained operation work, technical personnel or expert, governor but can judge and operate eas</p><p><b>  中文譯文:</b></p><p><b>  可編程控制器PLC</b></

96、p><p><b>  1 PLC簡(jiǎn)介</b></p><p>  可編程控制器是60年代末在美國(guó)首先出現(xiàn)的,當(dāng)時(shí)叫可編程邏輯控制器PLC(Programmable Logic Controller),目的是用來(lái)取代繼電器。以執(zhí)行邏輯判斷、計(jì)時(shí)、計(jì)數(shù)等順序控制功能。提出PLC概念的是美國(guó)通用汽車公司。PLC的基本設(shè)計(jì)思想是把計(jì)算機(jī)功能完善、靈活、通用等優(yōu)點(diǎn)和繼電器控制系統(tǒng)

97、的簡(jiǎn)單易懂、操作方便、價(jià)格便宜等優(yōu)點(diǎn)結(jié)合起來(lái),控制器的硬件是標(biāo)準(zhǔn)的、通用的。根據(jù)實(shí)際應(yīng)用對(duì)象,將控制內(nèi)容編成軟件寫入控制器的用戶程序存儲(chǔ)器內(nèi),使控制器和被控對(duì)象連接方便。 </p><p>  70年代中期以后,PLC已廣泛地使用微處理器作為中央處理器,輸入輸出模塊和外圍電路也都采用了中、大規(guī)模甚至超大規(guī)模的集成電路,這時(shí)的PLC已不再是僅有邏輯(Logic)判斷功能,還同時(shí)具有數(shù)據(jù)處理、PID調(diào)節(jié)和數(shù)據(jù)通信功能

98、。國(guó)際電工委員會(huì)(IEC)頒布的可編程控制器標(biāo)準(zhǔn)草案中對(duì)可編程控制器作了如下的定義:可編程控制器是一種數(shù)字運(yùn)算操作的電子系統(tǒng),專為在工業(yè)環(huán)境下應(yīng)用而設(shè)計(jì)。它采用了可編程序的存儲(chǔ)器,用來(lái)在其內(nèi)部存儲(chǔ)執(zhí)行邏輯運(yùn)算,順序控制、定時(shí)、計(jì)數(shù)和算術(shù)運(yùn)算等操作的指令,并通過(guò)數(shù)字式和模擬式的輸入和輸出,控制各種類型的機(jī)械或生產(chǎn)過(guò)程??删幊炭刂破骷捌溆嘘P(guān)外圍設(shè)備,易于與工業(yè)控制系統(tǒng)聯(lián)成一個(gè)整體,易于擴(kuò)充其功能的設(shè)計(jì)。 </p><p&

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