【正文】 single work, the half a work and the difference of a workers .The meaning of the single work also is to say both, a can send out only, but a can receive only, for example a spy he can receive the designation of the superior only, but can39。s address and saving machine three big pieces to constitute, CPU core is from an or many is tired to add the machine to constitute, mathematics that they have the logic operation ability, and can read the procedure save the contents of the machine to drive the homologous saving machine and I/ Os to connect after pass the calculation。PLC technique discussion and future development Along with the development of the ages, the technique that is nowadays is also gradually perfect, the petition plays more strong。 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 calculations 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。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 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 body now its value, at the PLC and correspondence between PLCs, can pass the munication of the information and the share of the dates 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。s request. This kind of breaks off the medium interruption to also became to break off the set. The Class that certainly break off is relevant according to various resources of CPU with internal PLC, also following a heap of capacity size of also relevant fasten. The contents that break off has a lot of kinds, for example the exterior break off, correspondence in of send out and accept the interruption and settle and the clock that count break off, still have the WDT to reset the interruption etc., they enriched the CPU to respond to the category while handle various business. Speak thus perhaps you can39。 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(shè)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(yīng)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(fù)雜的寄存器設(shè)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(shè)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。 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