【正文】 phrases perhaps: crash, the meaning that is mostly is a workload of CPU to lead greatly, the internal resources shortage etc. the circumstance can39。 But whole pair works is both can send out and accept the data, and can send out and accept at the same time. Be like the Inter is a typical example. The process that information transport also has synchronous and different step cent: The data line and the clock lines are synchronous when synchronous meaning lie in sending out the data, is also the data signal and the clock signals to be carry on by the CPU to send out at the same time, this needs to all want the specialized clock signal each other to carry on the transmission and connect to send, and is constrained, the characteristics of this kind of method lies in its speed very quick, but correspond work time of take up the CPU and also want to be long oppositely, at the same time the technique difficulty also very big. Its request lies in can39。s power, the one who make operate reduces the otiose error. Currently the HMI factory is also more and more, the function is also more and more strong, the price is also more and more low, the noodles of the usage are wide more and more. The HMI foreground can say that think 176。s brain and calculators, with the mode that person39。組態(tài)軟件可以將所有的這些硬件連接起來，通 過更直觀的動畫圖片來進行控制，并可以通過互聯(lián)網(wǎng)在異地進行控制，像神舟五號的發(fā)射就是采用這種辦法來使飛船升空。有一點可以說明的是我們一般會把急停按鈕的外部中斷升至最高級別，從而保證安全。 CPU 總是按照我們的意愿去做應該做的事情，但你錯誤的給它一件事情，它也會同樣的去做，這一點我們必須注意。 而異步是應用范圍最廣泛 的，這得益于它的技術(shù)難度相對要小、同時不需要配制專門的時鐘信號、它的特點在于，它的數(shù)據(jù)是間隔性的，離散性的發(fā)送和接受，當 CPU太忙的時候可以停頓性去工作，在硬件上也減少了難度，同時數(shù)據(jù)的丟失相對要少，我們可以通過數(shù)據(jù)的檢測來觀察我們發(fā)送的數(shù)據(jù)是否有錯誤，像奇偶法、累加法和八位效驗法等，都可以用來幫助我們檢測發(fā)送的數(shù)據(jù)是否有錯誤發(fā)生，通過反饋來進行辨別。 PLC 的數(shù)據(jù)傳送只是將內(nèi)部的數(shù)據(jù)傳送到對方的一塊連續(xù)的地址中，我們把它稱為一個表，對方的 PLC 通過讀取表中的數(shù)據(jù)來進行操作。并且能夠通過編寫功能幫助程序來提供各種力所能及的幫助，使得操作者減少不必 要的失誤。單靠人工的操作已不能滿足 于目前的制造業(yè)前景 ,也無法保證更高質(zhì)量的要求和高新技術(shù)企業(yè)的形象 . 人們在生產(chǎn)實踐中看到 ,自動化給人們帶來了極大的便利和產(chǎn)品質(zhì)量上的保證 ,同時也減輕了人員的勞動強度 ,減少了人員上的編制 .在許多復雜的生產(chǎn)過程中難以實現(xiàn)的目標控制、整體優(yōu)化、最佳決策等 ,熟練的操作工、技術(shù)人員或?qū)＜摇⒐芾碚邊s能夠容易判斷和操作 ,可以獲得滿意的效果 .人工智能的研究目標正是利用計算機來實現(xiàn)、模擬這些智能行為 ,通過人腦與計算機協(xié)調(diào)工作 ,以人機結(jié)合的模式 ,為解決十分復雜的問題尋找最佳的途徑 我們在各種場合看到了繼電器連接的控制，那已經(jīng)是 時代的過去，如今的繼電器只能作為低端的基層控制模塊或者簡單的設備中使用到；而 PLC 的出現(xiàn)也成為了劃時代的主題，通過極其穩(wěn)定的硬件穿插靈活的軟件控制，使得自動化走向了新的高潮。 以上僅僅是 PLC 的優(yōu)點之一，這也是人們比較容易理解的一部分，在很多的設備中，人們已不再希望看到太多的控制按鈕，它們不但容易損壞而且極易產(chǎn)生人為的失誤，小的并不是主要的失誤也許你還能夠 接受；但過大的甚至是致命的失誤是我們無法容忍的。這樣通過信息共享來使得兩者之間鏈接起來，形成一個共體，從而使的兩者間的配合更加的緊密，在彼此間達到映影相揮的效果。 信息輸送的過程也 有同步和異步之分：同步的意義在于發(fā)送數(shù)據(jù)時數(shù)據(jù)線和時鐘線是同步的，也就是數(shù)據(jù)信號和時鐘信號同時由 CPU 進行發(fā)送，這需要彼此都要專門的時鐘信號來進行傳送和接送，并且是強制性的，這種方法的特點在于它的速度極快、但相應占用 CPU的工作時間也相對的要長、同時技術(shù)難度也非常的大。 很多的情況下我們總喜歡采用串并轉(zhuǎn)換芯片來進行傳輸，這種情況下不需要我們進行過于復雜的寄存器設置了，而直接通過數(shù)據(jù)傳送指令進行數(shù)據(jù)交流，但在通信中并不是一個十大連水產(chǎn)學院本科畢業(yè)論文 外文翻譯 分可行的辦法，因為在發(fā)送數(shù)據(jù)的時候?qū)Ψ降?PLC 必須一直等待你的數(shù)據(jù) 輸出，它不能去做其他的工作。這樣講也許你并不能完全理解中斷的內(nèi)部結(jié)構(gòu)和操作順序，我們做一個小小的例子來說明 . 每一個設備總是不會忘記有一個按鈕，它也是在我們遇到緊急情況時使用的，那就是急停按鈕。 PLC 也有類似的情況，在 PLC 內(nèi)部有一個看門狗 WDT，我們可以設置 WDT一個程序運行的時間，當程序運行過程中出現(xiàn)程序跳轉(zhuǎn)錯誤時或者程序繁忙時，程序的運行時間超過 WDT 的設置時間， CPU 轉(zhuǎn)而 WDT 復位狀態(tài)。t satisfied with the current manufacturing industry foreground, also can39。 The saving machine can deposit the data that the I/ O input in the saving machine, and in work adjusting to bee tired to add the machine and I/ Os to connect, saving machine separately saving machine RAM of the procedure saving machine ROM and datas, the ROM can can do deposit of the data permanence in the saving machine, but RAM only for the CPU putes the temporary calculation usage of hour of buffer space. The PLC anti interference is very and excellent, our root need not concern its service life and the work situation bad, these all problems have already no longer bee the topic that we fail, but stay to our is a concern to e to internal resources of make use of the PLC to strengthen the control ability of the equipments for us, make our equipments more gentle. PLC language is not we imagine of edit collected materials the language or language of Cs to carry on weaving the distance, but the trapezoid diagram that the adoption is original after the electric appliances to control, make the electrical engineering teacher while weaving to write the procedure very easy prehended the PLC language, and a lot of non electricity professional also very quickly know and go deep into to the PLC. Is PLC one of the advantage above and only, this is also one part that the people prehend more and easily, in a lot of equipmentses, the people have already no longer hoped to see too many control buttons, they damage not only and easily and produce the artificial error easiest, small is not a main error perhaps you can still accept。 A work of half is also 2 and can can send out similar to acce