【正文】 means that each PLC controller can programmed through a puter if you have the software needed for programming. Today’s transmission puters are ideal for reprogramming a PLC controller in factory itself. This is of great importance to industry. Once the system is corrected, it is also important to read the right program into a PLC again. It is also good to check from time to time whether program in a PLC has not changed. This helps to avoid hazardous situations in factory rooms (some automakers have established munication works which regularly check programs in PLC controllers to ensure execution only of good programs). Almost every program for programming a PLC controller possesses various useful options such as: forced switching on and off of the system input/outputs (I/O lines), program follow up in real time as well as documenting a diagram. This documenting is necessary to understand and define failures and malfunctions. Programmer can add remarks, names of input or output devices, and ments that can be useful when finding errors, or with system maintenance. Adding ments and remarks enables any technician (and not just a person who developed the system) to understand a ladder diagram right away. Comments and remarks can even quote precisely part numbers if replacements would be needed. This would speed up a repair of any problems that e up due to bad parts. The old way was such that a person who developed a system had protection on the program, so nobody aside from this person could understand how it was done. Correctly documented ladder diagram allows any technician to understand thoroughly how system functions. Electrical supply is used in bringing electrical energy to central processing unit. Most PLC controllers work either at 24 VDC or 220 VAC. On some PLC controllers you’ll find electrical supply as a separate module. Those are usually bigger PLC controllers, while small and medium series already contain the supply module. User has to determine how much current to take from I/O module to ensure that electrical supply provides appropriate amount of current. Different types of modules use different amounts of electrical current. This electrical supply is usually not used to start external input or output. User has to provide separate supplies in starting PLC controller inputs because then you can ensure so called “pure” supply for the PLC controller. With pure supply we mean supply where industrial environment can not affect it damagingly. Some of the smaller PLC controllers supply their inputs with voltage from a small supply source already incorporated into a PLC. 中文 PLC 發(fā)展和市場條件 PLC 發(fā)展歷史 可編程邏輯控制器的英文名字是可編程序控制器，在 20 世紀 7080 年齡不斷的縮寫是 PC。s to 9039。s, the personal puter develops, also the abbreviation is PC。 in the 20th century 7080 age continuously abbreviation is PC. As a result of to the 9039。 As well as the massive switches quantity, the arteries impulse, the time, the counter, the simulation quantity reports to the police and so on the condition quantity primarily data acquisition surveillance. As a result of these controls and surveillance request, therefore PLC developed the substitution relay line and carries on the sequential control primarily product. In many years production practice, has gradually formed PLC, DCS and the IPC tripod sets up the potential, like table 1, but also has other single return route intelligence type regulators and so on to account for the certain percentage in the market. In the 8039。 If the I/O template are many time, may connect I/O by the CPU female board after the I/O expansion electric cable to expand the female board, installs the I/O template in above。隨著集成電路技術(shù)和計算機技術(shù)的發(fā)展，現(xiàn)在已經(jīng)第五代的 PLC 產(chǎn)品 。 在 80 至 90 年代的中間階段，是 PLC 發(fā)展最快的時間，每年的速率不斷維護是 30 ~ 40%。作為原則、 技術(shù)和工藝沒有最先進的技術(shù)難度產(chǎn)品，那么長時間一樣勤，是可以制造行業(yè)的窗體。因此，需要應(yīng)用 PLC 情況很多，在我們國家也是這樣。分點，依法可分為： 微型 PLC： 32 I/O 小型 PLC： 256 I/O 中小型 PLC： 1,024 I/O 無 錫 職 業(yè) 技 術(shù) 學(xué) 院 畢業(yè)設(shè)計說明書（英文翻譯） 7 大型 PLC： 4,096 I/O 巨人 PLC： 8,195 I/O 近年來已支持 300 回程路線的單一平面及以上 65,000 I/O 大型系統(tǒng)函授中小型 PLC、 使用 16 ~ 32 位 CPU、 微、 小型 PLC 最初使用 8 CPU，現(xiàn)在可以根據(jù)等等方面的通信要求，有些還改為 16 ~ 32 位 CPU。這一切解釋 PLC 廠硬件用戶發(fā)展的各個部分，便于用戶選擇，處置的規(guī)模不同的 PLC，此外處置，開放硬件制造商，零售業(yè)務(wù) (代理商 )、 系統(tǒng)集成業(yè)務(wù)，最終用戶來自市場供應(yīng)極大地方便了，這是一大成功經(jīng)驗。它加工溫度、 壓力、 當(dāng)前容量的不同，系統(tǒng)與 DCS 系統(tǒng)參數(shù)等使用掃描周期的快速游，一般為 ~ ，更快地選擇 50ms 年或較小掃描周期。模塊式 PLC包括 CPU 模塊、 I/O 模塊、內(nèi)存、電源模塊、底板或機架，這些模塊可以按照一定規(guī)則組合配置。運算器用于進行數(shù)字或邏輯運算，在控制器指揮下工作。除了這個操作系統(tǒng)之外，它還包括一個由梯形圖翻譯成而進制形式的用戶程序。在應(yīng)用程序開發(fā)中，通過一個串行電纜可以對程序存儲器進行重新編程。每一個輸入和輸出無 錫 職 業(yè) 技 術(shù) 學(xué) 院 畢業(yè)設(shè)計說明書（英文翻譯） 8 在存儲器中都有一個相應(yīng)的位。實際上，這意味著，如果你有編程所需要的軟件，早期 PLC 控制器可以通過計算機進行編程。定期檢查 PLC 中的程序是否改變是非常好的事情。程序員可以添加標記，書日和輸出設(shè)備名稱，以及對于查找錯誤或者對于系統(tǒng)維護很有用的注釋。響應(yīng)的舊方法是這樣的，開發(fā) 系統(tǒng)的人必須保護這個程序，他旁邊再沒有人知道系統(tǒng)是怎樣完成的。在有些 PLC 控制器上，你可以看見作為獨立模塊的電源。用戶必須提供獨立的電源來啟動 PLC 控制器的輸入和輸出，因為這樣可以保證 PLC 控制器的所謂 “純電源 ”。如果你正在進行機械制造，產(chǎn)品包裝，材料處理，自動化裝配及無數(shù)其他工業(yè)生產(chǎn)，你可能已經(jīng)用到了PLC。我們可以認為掃描周期是由三個主要階段組成的。 第一個 PLC 控制器是簡單的設(shè)備。今天的 PLC 控制器已經(jīng)可以處理高度復(fù)雜的任務(wù)，例如位置控制，不同規(guī)則控制以及其他復(fù)雜的應(yīng)用。 中央處理單元（ CPU）是 PLC 控制器的大腦。CPU還處理通信，連接 PLC 控制器的其他部件，運行程序，操作存儲器，監(jiān)控輸入和設(shè)置輸出。 PLC 使用系統(tǒng)存儲器（現(xiàn)在大部分采用閃存技術(shù)了）用于過程控制系統(tǒng)。由于快擦型存儲器技術(shù)的應(yīng)用，使得這個過程大大縮短了。一個輸入的實際狀態(tài)存儲狀態(tài)存儲在專用存儲器位上，為“ 1”或者“ 0”。 PLC 控制器可以通過計算機（通 常方式）重新編程，但是也可以通過人工編程器 9控制臺）編程。一旦系統(tǒng)修改結(jié)束，將正確的程序重新讀入PLC 控制器也是非常重要的。圖表驗證對于理解、定義失敗和故障非常必要。這將加快由于損壞零件而引起的任何問題的修理速度。大部分 PLC 控制器的工作電壓為 24VDC 或者220VAC。 該電源一般不用于啟動外部輸入或輸出。