【正文】 ，也具有優(yōu)先性，PLC 具備了這樣的功能。 CPU 總是按照我們的意愿去做應(yīng)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。這種中斷中的中斷也就形成了中斷嵌套。 中斷的內(nèi)容有很多種，比如外部中斷、通信中的發(fā)送和接受中斷、定時和計數(shù)的時鐘中斷、還 有 WDT 復(fù)位中斷等，它們豐富了 CPU 在處理各種事務(wù)時響應(yīng)種類。當我們遇到人身事故和意外情況時我們只要按下它，機器立即停止所有的操作，并等待處理完意外后再恢復(fù)操作。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。它在 PLC 執(zhí)行程序時一旦發(fā)現(xiàn)高級計數(shù)器對應(yīng)的中斷，就會立即放下手上的工作。 你也許聽過太多的這個詞 :“ 死機 ” ，大致的意思是 CPU工作量過大，內(nèi)部資源不足等情況造成程序無法運行。程序重新開始運行，但對中斷不會進行破壞。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。 PLC 的出現(xiàn)已經(jīng)足足影響了幾代人，我們也從上一輩的經(jīng)驗中獲取了更多的知識和教訓(xùn)，來不斷的發(fā)展 PLC 技術(shù)，將它推向更高浪潮。 the operation that list depends the artificial has already can39。t guarantee the request of the higher quantity and high new the image of the technique business enterprise. The people see in produce practice, automate brought the tremendous convenience and the product quantities for people up of assurance, also eased the personnel39。s brain and calculators, with the mode that person39。And the PLC emergence also became the epochmaking topic, adding the vivid software control through a very and stable hardware, making the automation head for the new high tide. The PLC biggest characteristics lie in: The electrical engineering teacher already no longer electric hardware up too many calculationses of cost, as long as order the importation that the button switch or the importation of the sensors order to link the PLC up can solve problem, pass to output to order the conjunction contact machine or control the start equipments of the big power after the electric appliances, but the exportation equipments direct conjunction of the small power can. PLC internal containment have the CPU of the CPU, and take to have an I/ O for expand of exterior to connect a people39。 The I/ O add inner part is tired the input and output system of the machine and exterior link, and deposit the related data into the procedure saving 外文翻譯 machine or data saving machine。 But lead even is a fatal error greatly is what we 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。t guarantee the equipments by the control of the single machine, but pass the information exchanges of the equipments and equipments to attain the result that we want. For example fore pack and the examination of the empress work preface, we will arrive wrapping information feedback to examine the place, and examine the information of the place to also want the 外文翻譯 feedback to packing. Pass the information share thus to make both the chain connect, being a total body, the match of your that thus make is more close, at each other attain to reflect the result that mutually flick. The PLC correspondence has already e more more body now its value, at the PLC and correspondence between PLCs, can pass the munication of the information and the share of the datas to guarantee that of the equipments moderates mutually, the result that arrive already to repair with each other. Data conversion the adoption RS232 between PLC connect to e to the transmission data, but the RS232 pick up a people and can guarantee 10 meters only of deliver the distance, if in the distance of 1000 meters we can pass the RS485 to carry on the correspondence, the longer distance can pass the MODEL only to carry on deliver. The PLC data transmission is just to be called a form to it in a piece of and continuous address that the data of the inner part delivers the other party, we, the PLC of the other party passes to read data in the watch to carry on the operation. If the data that data in the watch is a to establish generally, that is just the general data transmission, for example today of oil price rise, I want to deliver the price of the oil price to lose the oil ally on board, that is the share of the data。t give the superior reply。t send out and accept at the same time, for example when you make a phone call is to 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