基于PLC控制的物料分揀系統(tǒng)設(shè)計(jì)【說明書+開題+答辯資料】

資源目錄里展示的全都有預(yù)覽可以查看的噢，，下載就有,,請放心下載，原稿可自行編輯修改=【QQ：11970985 可咨詢交流】====================喜歡就充值下載吧。。。資源目錄里展示的全都有，，下載后全都有,,請放心下載，原稿可自行編輯修改=【QQ：197216396 可咨詢交流】==================== 答答 辯辯 人：人：機(jī)械電氣工程學(xué)院機(jī)械電氣工程學(xué)院論文題目論文題目：基于基于PLC控制的物料分揀系統(tǒng)設(shè)計(jì)控制的物料分揀系統(tǒng)設(shè)計(jì)學(xué)學(xué) 號：號：專專 業(yè)：電氣工程及其自動化業(yè)：電氣工程及其自動化院院 系：系：指導(dǎo)老師：指導(dǎo)老師：本科生畢業(yè)答辯本科生畢業(yè)答辯工作量2011級 石河子大學(xué) 機(jī)械電氣工程學(xué)院 電氣工程及其自動化系 劉回石河子大學(xué)石河子大學(xué)畢業(yè)論文答辯 一、一、畢業(yè)畢業(yè)論論文文(設(shè)計(jì)設(shè)計(jì))開題報告一篇開題報告一篇 56785678字字二、二、畢業(yè)論文畢業(yè)論文(設(shè)計(jì)設(shè)計(jì))文獻(xiàn)綜述一篇文獻(xiàn)綜述一篇 30153015字字四四、基于基于PLCPLC控制的物料分揀系統(tǒng)設(shè)計(jì)一份控制的物料分揀系統(tǒng)設(shè)計(jì)一份 1516515165字字五五、基于基于PLCPLC控制的物料分揀系統(tǒng)仿控制的物料分揀系統(tǒng)仿真一真一個個六六、基于基于PLCPLC控制的物料分揀仿真系統(tǒng)視屏錄像四個控制的物料分揀仿真系統(tǒng)視屏錄像四個三三、外文翻譯一篇、外文翻譯一篇 1328013280字字 目 錄 Catalogue石河子大學(xué)石河子大學(xué)畢業(yè)論文答辯目的和意義目的和意義軟硬件基軟硬件基本結(jié)構(gòu)本結(jié)構(gòu)調(diào)試調(diào)試總結(jié)總結(jié) 2011級 石河子大學(xué) 機(jī)械電氣工程學(xué)院 電氣工程及其自動化系 劉回設(shè)計(jì)主設(shè)計(jì)主要內(nèi)容要內(nèi)容目的意義 Purpose&importance 2011級 石河子大學(xué) 機(jī)械電氣工程學(xué)院 電氣工程及其自動化系 劉回石河子大學(xué)石河子大學(xué)畢業(yè)論文答辯 物料分揀系統(tǒng)作為前沿的產(chǎn)品應(yīng)自動化設(shè)物料分揀系統(tǒng)作為前沿的產(chǎn)品應(yīng)自動化設(shè)備更新時的需要，可以大量代替單調(diào)往復(fù)或高精備更新時的需要，可以大量代替單調(diào)往復(fù)或高精度需求的工作，在先進(jìn)制造領(lǐng)域中扮演著極其重度需求的工作，在先進(jìn)制造領(lǐng)域中扮演著極其重要的角色。它可以搬運(yùn)貨物、分揀物品、代替人要的角色。它可以搬運(yùn)貨物、分揀物品、代替人的繁重勞動?？梢詫?shí)現(xiàn)生產(chǎn)的機(jī)械化和自動化，的繁重勞動。可以實(shí)現(xiàn)生產(chǎn)的機(jī)械化和自動化，能在高溫、腐蝕及有毒氣體等環(huán)境下操作以保護(hù)能在高溫、腐蝕及有毒氣體等環(huán)境下操作以保護(hù)人身安全，可以廣泛應(yīng)用于機(jī)械制造、冶金、電人身安全，可以廣泛應(yīng)用于機(jī)械制造、冶金、電子、輕工業(yè)和原子能等部門。子、輕工業(yè)和原子能等部門?；窘Y(jié)構(gòu)基本結(jié)構(gòu) 石河子大學(xué)石河子大學(xué)畢業(yè)論文答辯系統(tǒng)的組成物料分揀系統(tǒng)由物料分揀系統(tǒng)由上料機(jī)構(gòu)、搬運(yùn)上料機(jī)構(gòu)、搬運(yùn)機(jī)械手、皮帶輸機(jī)械手、皮帶輸送線、物件分揀送線、物件分揀等機(jī)構(gòu)組成，通等機(jī)構(gòu)組成，通過過PLC連接控制連接控制的模的模擬一擬一體化生體化生產(chǎn)線。其產(chǎn)線。其PLC控控制工作流程圖制工作流程圖如如左左圖圖基本結(jié)構(gòu)基本結(jié)構(gòu) 石河子大學(xué)石河子大學(xué)畢業(yè)論文答辯2011級 石河子大學(xué) 機(jī)械電氣工程學(xué)院 電氣工程及其自動化系 劉回一一 上上料機(jī)構(gòu)料機(jī)構(gòu)基本結(jié)構(gòu)基本結(jié)構(gòu)石河子大學(xué)石河子大學(xué)畢業(yè)論文答辯2011級 石河子大學(xué) 機(jī)械電氣工程學(xué)院 電氣工程及其自動化系 劉回二二.搬運(yùn)機(jī)械手機(jī)構(gòu)搬運(yùn)機(jī)械手機(jī)構(gòu)基本結(jié)構(gòu)基本結(jié)構(gòu)石河子大學(xué)石河子大學(xué)畢業(yè)論文答辯2011級 石河子大學(xué) 機(jī)械電氣工程學(xué)院 電氣工程及其自動化系 劉回3.皮帶輸送與分揀機(jī)構(gòu)皮帶輸送與分揀機(jī)構(gòu)三三 物物料料分分揀揀機(jī)機(jī)構(gòu)構(gòu)主要內(nèi)容主要內(nèi)容石河子大學(xué)石河子大學(xué)畢業(yè)論文答辯2011級 石河子大學(xué) 機(jī)械電氣工程學(xué)院 電氣工程及其自動化系 劉回PLC的選型的選型模擬系統(tǒng)對模擬系統(tǒng)對PLC的要的要求求1、I/O點(diǎn)數(shù)要求點(diǎn)數(shù)要求系統(tǒng)所需輸入點(diǎn)數(shù)為系統(tǒng)所需輸入點(diǎn)數(shù)為26點(diǎn)；點(diǎn)；系統(tǒng)所需輸出點(diǎn)數(shù)為系統(tǒng)所需輸出點(diǎn)數(shù)為14點(diǎn)。點(diǎn)。在實(shí)際統(tǒng)計(jì)出的在實(shí)際統(tǒng)計(jì)出的I/O點(diǎn)數(shù)的基礎(chǔ)上加點(diǎn)數(shù)的基礎(chǔ)上加15%20%的備用量，以便今后調(diào)整和擴(kuò)展。的備用量，以便今后調(diào)整和擴(kuò)展。2、確定型號確定型號考考慮到慮到FX2N-64MT與與FX2N-48MT相比價格稍微較相比價格稍微較貴。但貴。但FX2N-48MT的輸入點(diǎn)數(shù)能不能滿足系統(tǒng)要的輸入點(diǎn)數(shù)能不能滿足系統(tǒng)要求求，最后確定可編程控制器型號為：三菱最后確定可編程控制器型號為：三菱FX2N-64MT主要內(nèi)容主要內(nèi)容石河子大學(xué)石河子大學(xué)畢業(yè)論文答辯2011級 石河子大學(xué) 機(jī)械電氣工程學(xué)院 電氣工程及其自動化系 劉回輸入輸入/輸出點(diǎn)分配輸出點(diǎn)分配3、輸入點(diǎn)分配、輸入點(diǎn)分配主要內(nèi)容主要內(nèi)容石河子大學(xué)石河子大學(xué)畢業(yè)論文答辯2011級 石河子大學(xué) 機(jī)械電氣工程學(xué)院 電氣工程及其自動化系 劉回輸入輸入/輸出點(diǎn)分配輸出點(diǎn)分配4、輸出點(diǎn)分配輸出點(diǎn)分配主要內(nèi)容主要內(nèi)容石河子大學(xué)石河子大學(xué)畢業(yè)論文答辯2011級 石河子大學(xué) 機(jī)械電氣工程學(xué)院 電氣工程及其自動化系 劉回PLC控制原理圖控制原理圖調(diào) 試 畢業(yè)論文答辯2011級 石河子大學(xué) 機(jī)械電氣工程學(xué)院 電氣工程及其自動化系 劉回石河子大學(xué)石河子大學(xué)軟件調(diào)試軟件調(diào)試 需要進(jìn)行離線測試，既不需要進(jìn)行離線測試，既不將將PLC的輸出接到設(shè)備上。按的輸出接到設(shè)備上。按照控制要求在指定輸入端輸入照控制要求在指定輸入端輸入信號，觀察輸出指示燈的狀態(tài)，信號，觀察輸出指示燈的狀態(tài)，若輸出不符合要求，則查找原若輸出不符合要求，則查找原因，并排除之。因，并排除之。總 結(jié) Summarize石河子大學(xué)石河子大學(xué)畢業(yè)論文答辯 物料分揀采用可編程控制器物料分揀采用可編程控制器PLC 進(jìn)行控制，進(jìn)行控制，能連續(xù)、大批量地分揀貨物，分揀誤差率低且勞動強(qiáng)能連續(xù)、大批量地分揀貨物，分揀誤差率低且勞動強(qiáng)度大大降低，可顯著提高勞動生產(chǎn)率。而且，分揀系度大大降低，可顯著提高勞動生產(chǎn)率。而且，分揀系統(tǒng)能靈活地與其他物流設(shè)備無縫連接，實(shí)現(xiàn)對物料實(shí)統(tǒng)能靈活地與其他物流設(shè)備無縫連接，實(shí)現(xiàn)對物料實(shí)物流、物料信息流的分配和管理。物流、物料信息流的分配和管理。其設(shè)計(jì)采用標(biāo)準(zhǔn)化、其設(shè)計(jì)采用標(biāo)準(zhǔn)化、模塊化的組裝，具有系統(tǒng)布局靈活，維護(hù)、檢修方便模塊化的組裝，具有系統(tǒng)布局靈活，維護(hù)、檢修方便等特點(diǎn)，受場地原因影響不大。等特點(diǎn)，受場地原因影響不大。同時，只要根據(jù)不同同時，只要根據(jù)不同的分揀對象，對本系統(tǒng)稍加修改即可實(shí)現(xiàn)的分揀對象，對本系統(tǒng)稍加修改即可實(shí)現(xiàn)求求成品分揀機(jī)構(gòu)仿真成品分揀機(jī)構(gòu)仿真.avi 。2011級 石河子大學(xué) 機(jī)械電氣工程學(xué)院 電氣工程及其自動化系 劉回致謝！謝謝各位老師的指導(dǎo)畢業(yè)設(shè)計(jì)任務(wù)書 機(jī) 電 學(xué)院 電 氣 專業(yè) 2011 年級 課題名稱 基于PLC控制的物料分揀系統(tǒng)設(shè)計(jì) 畢業(yè)論文(設(shè)計(jì))起止時間 2015年3月1日--6月 (共12周) 指導(dǎo)教師 職稱 講師 學(xué)生姓名 學(xué)號 2011509020 任務(wù)下達(dá)日期 2015.3.1 課題內(nèi)容 本課題基于PLC控制物料分揀裝置的設(shè)計(jì)系統(tǒng)集成自動控制技術(shù)，檢測技術(shù)，傳感器技術(shù)于一體，根據(jù)利用物料分揀裝置的具體要求對系統(tǒng)的設(shè)計(jì)思路提出自己的觀點(diǎn)（如：系統(tǒng)整體設(shè)計(jì)、軟硬件選擇與設(shè)計(jì)等），提出整體系統(tǒng)設(shè)計(jì)方案，并對該方案進(jìn)行仿真并就可能出現(xiàn)的問題提出應(yīng)對措施。 課題任務(wù)的具體要求 1.整理搜集的資料，撰寫開題報告及文獻(xiàn)綜述。 2.設(shè)計(jì)說明書一份（包括原始資料，設(shè)計(jì)要求、目的和意義，計(jì)算說明書，參考文獻(xiàn)，中英文摘要，收獲與體會等） 3.完成軟件的調(diào)試和仿真。 擬定的工作進(jìn)度（以周為單位） 1—4周，搜集資料，提出幾種可行的方案 5—8周，資料分類與整理，整體思路的策劃，確定設(shè)計(jì)方案； 9—12周，整理試驗(yàn)數(shù)據(jù)，撰寫設(shè)計(jì)說明書（準(zhǔn)確，客觀）,準(zhǔn)備答辯 主要參考文獻(xiàn) 1．向曉漢，王寶銀?編. 三菱FX系列PLC完全精通教程. 北京：化學(xué)工業(yè)出版社,2012. 2. 陳忠平?等 著. PLC自學(xué)手冊. 北京：人民郵電出版社,2009 3. 宋伯生?編. PLC編程實(shí)用指南. 北京：機(jī)械工業(yè)出版社,2007. 任務(wù)下達(dá)人（簽字） 日期： 2015年 3月 1日 任務(wù)接受人（簽字） 日期： 年 月 日 Programmable logic controller A programmable logic controller (PLC) or programmable controller is a digital computer used for automation of electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or lighting fixtures. PLCs are used in many industries and machines. 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. 1.History The PLC was invented in response to the needs of the American automotive manufacturing industry. Programmable logic controllers were initially adopted by the automotive industry where software revision replaced the re-wiring of hard-wired control panels when production models changed. Before the PLC, control, sequencing, and safety interlock logic for manufacturing automobiles was accomplished using hundreds or thousands of relays, cam timers, and drum sequencers and dedicated closed-loop controllers. The process for updating such facilities for the yearly model change-over was very time consuming and expensive, as electricians needed to individually rewire each and every relay. In 1968 GM Hydramatic (the automatic transmission division of General Motors) issued a request for proposal for an electronic replacement for hard-wired relay systems. The winning proposal came from Bedford Associates of Bedford, Massachusetts. The first PLC, designated the 084 because it was 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 DIgital 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 1977 to Gould Electronics, and later acquired by German Company AEG and then by French Schneider Electric, the current owner. One of the very first 084 models built is now on display at Modicon's headquarters in North Andover, Massachusetts. It was presented to Modicon by GM, when the unit was retired after nearly twenty years of uninterrupted service. Modicon used the 84 moniker at the end of its product range until the 984 made its appearance. The automotive industry is still one of the largest users of PLCs. 2.Development Early PLCs were designed to replace relay logic systems. These PLCs were programmed in "ladder logic", which strongly resembles a schematic diagram of relay logic. This program notation was chosen to reduce training demands for the existing technicians. Other early PLCs used a form of instruction list programming, based on a stack-based logic solver. Modern PLCs 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 programming language designed to program PLCs based on state transition diagrams. Many early PLCs did not have accompanying programming terminals that were capable of graphical representation of the logic, and so the logic was instead represented as a series of logic expressions in some version of Boolean format, similar to Boolean algebra. As programming terminals evolved, it became more common for ladder logic to be used, for the aforementioned reasons. Newer formats such as State Logic and Function Block (which is similar to the way logic is depicted when using digital integrated logic circuits) exist, but they are still not as popular as ladder logic. A primary reason for this is that PLCs solve the logic in a predictable and repeating sequence, and ladder logic allows the programmer (the person writing the logic) to see any issues with the timing of the logic sequence more easily than would be possible in other formats. 2.1Programming Early PLCs, up to the mid-1980s, were programmed using proprietary programming panels or special-purpose programming terminals, which often had dedicated function keys representing the various logical elements of PLC programs. Programs were stored on cassette tape cartridges. Facilities for printing and documentation were very minimal due to lack of memory capacity. The very oldest PLCs used non-volatile magnetic core memory. More recently, PLCs are programmed using application software on personal computers. The computer is connected to the PLC through Ethernet, RS-232, RS-485 or RS-422 cabling. The programming software allows entry and editing of the ladder-style logic. Generally the software provides functions for debugging and troubleshooting the PLC software, for example, by highlighting portions of the logic to show current status during operation or via simulation. The software will upload and download the PLC program, for backup and restoration purposes. In some models of programmable controller, the program is transferred from a personal computer to the PLC though a programming board which writes the program into a removable chip such as an EEPROM or EPROM. 3.Functionality 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 PLCs 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. Regarding the practicality of these desktop computer based logic controllers, it is important to note that they have not been generally accepted in heavy industry because the desktop computers run on less stable operating systems than do PLCs, and because the desktop computer hardware is typically not designed to the same levels of tolerance to temperature, humidity, vibration, and longevity as the processors used in PLCs. In addition to the hardware limitations of desktop based logic, operating systems such as Windows do not lend themselves to deterministic logic execution, with the result that the logic may not always respond to changes in logic state or input status with the extreme consistency in timing as is expected from PLCs. Still, such desktop logic applications find use in less critical situations, such as laboratory automation and use in small facilities where the application is less demanding and critical, because they are generally much less expensive than PLCs. In more recent years, small products called PLRs (programmable logic relays), and also by similar names, have become more common and accepted. These are very much like PLCs, and are used in light industry where only a few points of I/O (i.e. a few signals coming in from the real world and a few going out) are involved, and low cost is desired. These small devices are typically made in a common physical size and shape by several manufacturers, and branded by the makers of larger PLCs to fill out their low end product range. Popular names include PICO Controller, NANO PLC, and other names implying very small controllers. Most of these have between 8 and 12 digital inputs, 4 and 8 digital outputs, and up to 2 analog inputs. Size is usually about 4" wide, 3" high, and 3" deep. Most such devices include a tiny postage stamp sized LCD screen for viewing simplified ladder logic (only a very small portion of the program being visible at a given time) and status of I/O points, and typically these screens are accompanied by a 4-way rocker push-button plus four more separate push-buttons, similar to the key buttons on a VCR remote control, and used to navigate and edit the logic. Most have a small plug for connecting via RS-232 or RS-485 to a personal computer so that programmers can use simple Windows applications for programming instead of being forced to use the tiny LCD and push-button set for this purpose. Unlike regular PLCs that are usually modular and greatly expandable, the PLRs are usually not modular or expandable, but their price can be two orders of magnitude less than a PLC and they still offer robust design and deterministic execution of the logic. 4.PLC Topics 4.1.Features The main difference from other computers is that PLCs are armored for severe conditions (such as dust, moisture, heat, cold) and have the facility 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 positioning systems. Some use machine vision. On the actuator side, PLCs operate electric motors, pneumatic or hydraulic cylinders, magnetic relays, 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. 4.2System scale A small PLC will have a fixed number of connections built in for inputs and outputs. Typically, expansions are available if the base model has insufficient I/O. Modular PLCs have a chassis (also called a rack) into which are placed modules with different functions. The processor and selection of I/O modules is customised for the particular application. Several racks can be administered by a single processor, and may have thousands of inputs and outputs. A special high speed serial I/O link is used so that racks can be distributed away from the processor, reducing the wiring costs for large plants. 4.3User interface PLCs may need to interact with people for the purpose of configuration, alarm reporting or everyday control. A simple system may use buttons and lights to interact with the user. Text displays are available as well as graphical touch screens. More complex systems use a programming and monitoring software installed on a computer, with the PLC connected via a communication interface. 4.4Communications PLCs have built in communications ports, usually 9-pin RS-232, but optionally EIA-485 or Ethernet. Modbus, BACnet or DF1 is usually included as one of the communications protocols. Other options include various fieldbuses such as DeviceNet or Profibus. Other communications protocols that may be used are listed in the List of automation protocols. Most modern PLCs can communicate over a network to some other system, such as a computer running a SCADA (Supervisory Control And Data Acquisition) system or web browser. PLCs used in larger I/O systems may have peer-to-peer (P2P) communication between processors. This allows separate parts of a complex process to have individual control while allowing the subsystems to co-ordinate over the communication link. These communication links are also often used for HMI devices such as keypads or PC-type workstations. 4.5Programming PLC programs are typically written in a special application on a personal computer, then downloaded by a direct-connection cable or over a network to the PLC. The program is stored in the PLC either in battery-backed-up RAM or some other non-volatile flash memory. Often, a single PLC can be programmed to replace thousands of relays. Under 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. Initially most PLCs utilized Ladder Logic Diagram Programming, a model which emulated electromechanical control panel devices (such as the contact and coils of relays) which PLCs replaced. This model remains common today. 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 language) and SFC (Sequential function chart). These techniques emphasize logical organization of operations. While the fundamental concepts of PLC programming are common to all manufacturers, 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. 5.PLC compared with other control systems PLCs are well-adapted to a range of automation tasks. These are typically industrial processes in manufacturing where the cost of developing and maintaining the automation system is high relative to the total cost of the automation, and where changes to the system would be expected during its operational life. PLCs contain input and output devices compatible with industrial pilot devices and controls; little electrical design is required, and the design problem centers on expressing the desired sequence of operations. PLC applications 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 control systems are economic due to the lower cost of the components, which can be optimally chosen instead of a "generic" solution, and where the non-recurring engineering charges are spread over thousands or millions of units. For high volume or very simple fixed automation tasks, different techniques are used. For example, a consumer dishwasher would be controlled by an electromechanical cam timer costing only a few dollars in production quantities. A microcontroller-based design would be appropriate where hundreds 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 would 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 as transit busses economically use PLCs instead of custom-designed controls, because the volumes are low and the development cost would be uneconomic. 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 high-speed or precision controls may also require customized solutions; for example, aircraft flight controls. Programmable controllers are widely used in motion control, positioning control and torque control. Some manufacturers produce motion control units to be integrated with PLC so that G-code (involving a CNC machine) can be used to instruct machine movements. PLCs may include logic for single-variable feedback analog 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 PLCs were usually configured 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 PLCs have become more powerful, the boundary between DCS and PLC applications has become less distinct. PLCs have similar functionality as Remote Terminal Units. An RTU, however, usually does not support control algorithms or control loops. As hardware rapidly becomes more powerful and cheaper, RTUs, PLCs and DCSs are increasingly beginning to overlap in responsibilities, and many vendors sell RTUs with PLC-like features and vice versa. The industry has standardized on the IEC 61131-3 functional block language for creating programs to run on RTUs and PLCs, although nearly all vendors also offer proprietary alternatives and associated development environments. 6.Digital and analog signals 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 switches, 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, 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 undefined. Initially, PLCs had only discrete I/O. Analog signals are like volume 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 available to store the data. As PLCs 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. Analog signals can use voltage or current with a magnitude proportional to the value of the process signal. For example, an analog 0 - 10 V input or 4-20 mA would be converted into an integer value of 0 - 32767. 可編程邏輯控制器 可編程邏輯控制器（PLC）或可編程序控制器是用于機(jī)電過程自動化的數(shù)字計(jì)算機(jī)，例如控制機(jī)械廠生產(chǎn)線、游樂設(shè)施或照明裝置。可編程控制器在許多工業(yè)和機(jī)器中使用。與通用的計(jì)算機(jī)不同的是，PLC是專為多個輸入和輸出管理，擴(kuò)展溫度范圍、不受電磁噪音影響、抗震動和沖擊所設(shè)計(jì)?？刂破鞯牟僮鞒绦蛲ǔ４鎯υ陔姵毓╇娀蚍且资缘膬?nèi)存中。PLC是實(shí)時的系統(tǒng)，因?yàn)橄到y(tǒng)產(chǎn)生的輸出結(jié)果必須在有限的時間內(nèi)回饋到輸入，否則會導(dǎo)致錯誤操作。 1.歷史 PLC發(fā)明是針對于美國汽車制造行業(yè)的需要?？删幊踢壿嬁刂破髯畛跬ㄟ^了在軟件版本更換硬連線的控制板生產(chǎn)模式更改時的汽車工業(yè)。 在PLC之前，控制、程序化和安全聯(lián)鎖邏輯制造汽車是使用上百或上千的繼電器、凸輪計(jì)時器、鼓定序儀和專用的閉環(huán)控制器來完成的。在每年更新模型等設(shè)施轉(zhuǎn)變過程是非常耗時并且成本高昂的，這是因?yàn)殡姽ば枰獑为?dú)地再接電線給每個中轉(zhuǎn)。 在1968年 GM Hydramatic（自動輸電分局）發(fā)布通用汽車公司的提議，電子替代布線中繼系統(tǒng)。獲獎的提案來自貝得福得，馬薩諸塞的貝得福得同事。第一個PLC選定084，因?yàn)樗秦惖酶５猛碌牡诎耸膫€項(xiàng)目。貝得福得同事建立了一家新的公司致力開發(fā)、生產(chǎn)、銷售，和服務(wù)這一新產(chǎn)品：Modicon，代表模塊化數(shù)字控制器。迪克·莫利，被認(rèn)為是PLC之父，他是從事該項(xiàng)目的人之一。1977年古爾德電子公司當(dāng)前所有者收購法國施耐德電氣公司同德國公司AEG并售予該品牌為Modicon。 084模型之一首次被設(shè)在北部安多弗的Modicon總部馬薩諸塞州。這是專門為通用汽車服務(wù)的，并且經(jīng)過了近二十多年的不間斷服務(wù)。直至984出現(xiàn)，Modicon使用的84名字才在其產(chǎn)品范圍中結(jié)束。 汽車工業(yè)仍是PLC的最大用戶之一。 2.發(fā)展 早期的可編程控制器是設(shè)計(jì)來取代繼電器邏輯系統(tǒng)。這些可編程控制器的“階梯邏輯”是與繼電器邏輯示意圖非常類似的。選擇此程序表示法的目的是為了減少對現(xiàn)有技術(shù)人員的培訓(xùn)需求。其他早期的可編程控制器使用指令列表編程，基于一個堆棧編程邏輯求解器進(jìn)行求解。 現(xiàn)代可編程控制器在各種各樣的方式可以被編程，從梯形邏輯語言到更加傳統(tǒng)的編程語言例如BASIC和C語言。另一個方法是狀態(tài)邏輯，被設(shè)計(jì)的一種非常高級編程語言根據(jù)狀態(tài)轉(zhuǎn)換圖的可編程控制器編程。 很多早期可編程控制器沒有可編程終端的邏輯圖形表示法，邏輯反而是被描繪成一系列在一些版本的布爾格式的邏輯表達(dá)式，類似于布爾代數(shù)。隨著編程碼發(fā)展，由于上述原因它變成更常見的梯形邏輯語言。更新的格式如國家邏輯和功能塊（這是類似的邏輯描述使用數(shù)字邏輯集成電路時的方式）的存在，但它們?nèi)詻]有梯形邏輯語言流行。一個主要原因是可編程控制器解決問題用一個可預(yù)測和重復(fù)的序列的邏輯，并且梯形邏輯語言可以用其他格式讓程序員（寫邏輯）的人看到邏輯的時間，所有問題更加容易地程序化。 2.1編程 早期的PLC，到80年代中期，都是用專有的編程版或?qū)Ｓ镁幊探K端，往往有專門的功能鍵，代表各種PLC程序邏輯元件。程序存儲在盒式磁帶盒上。由于缺少的內(nèi)存容量很少用于打印設(shè)備。最古老的可編程控制器使用的是非易失性磁核心內(nèi)存。 最期PLC在個人計(jì)算機(jī)上使用應(yīng)用軟件編程。計(jì)算機(jī)連接到PLC通過以太網(wǎng)RS-232,RS-485或RS-422纜線連接。編程軟件允許輸入梯式邏輯編程。通常，軟件提供了用于調(diào)試和故障排除的功能，例如在操作過程中或通過仿真的邏輯部分PLC軟件突出顯示當(dāng)前狀態(tài)。該軟件將上傳和下載PLC程序以便備份和恢復(fù)。在某些型號的PLC中雖然程序?qū)懭胍粋€可移動的芯片，如EEPROM或EPROM，但該方案還是得從個人電腦傳輸?shù)絇LC編程版。 3.功能 PLC的功能經(jīng)過多年的發(fā)展，包括連續(xù)的繼電器控制，運(yùn)動控制，過程控制，分布式控制系統(tǒng)和網(wǎng)絡(luò)。一些現(xiàn)代PLC的數(shù)據(jù)處理，存儲，處理能力和通信能力相當(dāng)于臺式電腦。PLC編程結(jié)合遠(yuǎn)程I/O硬件，一臺通用臺式計(jì)算機(jī)允許在某些應(yīng)用中重疊使用某一可編程控制器。在重工業(yè)中PLC被認(rèn)為沒有這些桌面計(jì)算機(jī)為主的邏輯控制器的實(shí)際性強(qiáng)，因?yàn)镻LC在臺式計(jì)算機(jī)系統(tǒng)中運(yùn)行不是很穩(wěn)定，并且，因?yàn)榕_式計(jì)算機(jī)硬件沒有被設(shè)計(jì)成耐溫度、濕氣、振動和耐用作為可編程控制器的處理器。除桌面基于邏輯的硬件局限之外，例如Windows操作系統(tǒng)不適合自己的確定性邏輯的執(zhí)行，結(jié)果是PLC邏輯不可能總是對規(guī)定邏輯變化的輸入狀態(tài)與極端性預(yù)計(jì)的時間一致。盡管如此，這樣桌面邏輯被應(yīng)用在較不重要情況，像實(shí)驗(yàn)室自動化和小型設(shè)施中使用該應(yīng)用程序的要求不高，因?yàn)樗麄兊膬r格一般都遠(yuǎn)遠(yuǎn)低于昂貴的PLC。 在最近數(shù)年，小產(chǎn)品稱為PLR（可編程邏輯繼電器），并且因?yàn)槊窒嗨疲兊酶Ｒ姴⒈唤邮?。這些很像PLC已經(jīng)應(yīng)用于輕工業(yè)，它只有少部分的輸入/輸出（例如一些真實(shí)的輸入輸出信號）參與，低成本，很理想。這些小設(shè)備尺寸和形狀比較普通地幾位制造商制作，并且由更大的PLC制作商來填滿他們低端產(chǎn)品規(guī)格。俗名包括PICO控制器、納米PLC和其他的小控制器。多數(shù)這些控制器有在8到12數(shù)字輸入、4到8數(shù)字輸出，多達(dá)2個模擬輸入。尺寸通常是4英寸寬、3英寸高、3英寸深。大多數(shù)這樣的設(shè)備有一個小郵票大小的液晶屏幕來觀看簡化梯子邏輯的輸入/輸出點(diǎn)（只有一小部分程序被可見于給定的時間）和狀況，并且這些屏幕由一個電磁四通搖臂按鈕操縱加上四個不同的用于瀏覽和編輯的邏輯電鈕，類似于錄像機(jī)遙控按鈕?？刂破鞔蠖鄶?shù)有一個小插座為通過連接RS-232或RS-485到個人計(jì)算機(jī)，以便程序員可能為編程使用簡單的窗口應(yīng)用而不是被迫使用微小的LCD和電鈕。不像普通PLC，通常是模塊化，大大擴(kuò)展,控制器通常不會取模塊化并且不是可擴(kuò)展的，但是他們提供穩(wěn)健設(shè)計(jì)的確定性和執(zhí)行邏輯的價值比PLC少。 4.可編程序控制器PLC 4.1未來發(fā)展 從其他計(jì)算機(jī)來看，主要區(qū)別是可編程控制器具有特殊條件（例如，灰塵、濕、熱、冷）和具有廣泛的輸入/輸出（I/O