【導(dǎo)讀】是以微處理器為核心的通用工業(yè)自動化裝置。是20世紀(jì)60年代末在繼電器控制。具體來說，PLC的特點表現(xiàn)為以下幾個。PLC專業(yè)在工業(yè)環(huán)境的惡劣條件下應(yīng)用而設(shè)計。度很大的環(huán)境中。在硬件設(shè)計方面，首先是選用優(yōu)質(zhì)器件，再就是采用合理的系。由于PLC本身具有很高的可靠性，所以在發(fā)生故障的部位大多集中在輸入/. PLC采用面向控制過程、面。在電信號匹配的情況下，PLC的接線。執(zhí)行控制任務(wù)的執(zhí)行元件與PLC輸出端子連接。種性能使PLC具有很高的經(jīng)濟(jì)效益。與替換故障部件，這樣的軟硬件設(shè)計就使現(xiàn)場電氣人員與技術(shù)人員易于使用。PLC可連接成為功能很強的網(wǎng)絡(luò)系統(tǒng)。PLC安裝簡單而且功能強大，其相對小的體積。從一開始，PLC便以易維護(hù)作為設(shè)計目標(biāo)。來利用PLC的內(nèi)部資源為我們加強設(shè)備的控制能力，使我們的設(shè)備更加的柔性。的語言，而且很多的非電氣專業(yè)人士也對PLC很快認(rèn)識并深入。你就知道了，它和PLC的結(jié)合給了我們更大的空間。它稱為一個表，對方的PLC通過讀取表中的數(shù)據(jù)來進(jìn)行操作。

　　

【正文】 out and accept, be the CPU is too busy of time can grind to a stop sex to work, also reduced the difficulty on the hardware, the data throw to lose at the same time opposite want to be little, we can pass the examination of the data to observe whether the data that we send out has the mistake or not, be like strange accidentally the method, tired addition and eight efficacies method etc., can use to helps whether the data that we examine to send out have or not the mistake occurrence, pass the feedback to carry on the discriminator. A line of transmission of the information contains a string of and bine the cent of: The usual PLC is 8 machines, certainly also having 16 machines. We can be an at the time of sending out the data a send out to the other party, also can be 88 send out the data to the other party, an and 8 differentiations are also the as that we say to send out the data and bine sends out the data. A speed is more and slowly, but as long as 2 or three lines can solve problem, and can use the telephone line to carry on the long range control. But bine the ocular transmission speed is very quick of, it is a string of ocular of 25600%, occupy the advantage in the short distance, the in view of the fact TTL electricity is even, being limited by the scope of one meter generally, it bine unwell used for the data transmission of the long pull, thus the cost is too expensive. Under a lot of circumstances we are total to like to adopt the string to bine the conversion chip to carry on deliver, under this kind of circumstance not need us to carry on to deposited the machine to establish too and plicatedly, but carry on the data exchanges through the data transmission instruction directly, but is not a very viable way in the correspondence, because the PLC of the other party must has been wait for your data exportation at the time of sending out the data, it can39。t do other works. When you are reading the book, you hear someone knock on door, you stop to start up of affair, open the door and bine to continue with the one who knock on door a dialogue, the telephone of this time rang, you signal hint to connect a telephone, after connecting the telephone through, return overdo e together knock on door to have a conversation, after dialogue plete, you continue again to see your book, this kind of circumstance we are called the interruption to it, it has the authority, also having sex of have the initiative, the PLC had such function .Its characteristics lie in us and may meet the urgently abrupt affairs in the operation process of the equipments, we want to stop to start immediately up of work, the whereabouts manages the more important affair, this kind of circumstance is we usually meet of, PLC while carry out urgent mission, total will keep the current appearance first, for example the address of the procedure, CPU of tired add the machine data etc., be like to stick down w hich the book that we see is when we open the door the page or simply make a mark, because we treat and would still need to continue immediately after book of see the behind. The CPU always does the affair that should do according to our will, but your mistake of give it an affair, it also would be same to do, this we must notice. The interruption is not only a, sometimes existing jointly with the hour several inside break, break off to have the preferred Class, they will carry out the interruption of the higher Class according to person39。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。t prehend the internal structure and operation orders of the interruption pletely also, we do a very small example to explain. Each equipment always will not fet a button, it also is at we meet the urgent circumstance use of, which is nasty to stop the button. When we meet the Human body trouble and surprised circumstances we as long as press it, the machine stops all operations immediately, and wait for processing the over surprised empress recover the operation again. Nasty stop the internal I/ O of the internal CPU of the button conjunction PLC to connect up, be to press button an exterior to trigger signal for CPU, the CPU carries on to the I/ O to examine again, being to confirm to have the exterior to trigger the signal, CPU protection the spot breaks off procedure counts the machine turn the homologous exterior I/ O automatically in the procedure to go to also, be exterior interruption procedure processing plete, the procedure counts the machine to return the main procedure to continue to work. Have 1:00 can what to explain is we generally would nasty stop the button of exterior break off to rise to the tallest Class, thus guarantee the safety. When we are work a work piece, giving the PLC a signal, counting PLC inner part the machine add 1 to pute us for a day of workload, a count the machine and can solve problem in brief, certainly they also can keep the data under the condition of dropping the electricity, urging the data not to throw to lose, this is also what we hope earnestly. The PLC still has the function that the high class counts the machine, being us while accept some dates of high speed, the high speed that here say is the data of the in all aspects tiny second class, for example the bar code scanner is scannin