【正文】
range 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 contain 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 differentiationses 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 oscular transmission speed is very quick of, it is a string of oscular 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 depositted 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。 PLC 的抗干擾是極其優(yōu)秀的,我們根本不用去關(guān)心它的使用壽命和工作場(chǎng)合的惡劣,這些所有的問(wèn)題已不再成為我們失敗的主題,而留給我們的是關(guān)心如何來(lái)利用 PLC 的內(nèi)部資源為我們加強(qiáng)設(shè)備的控制能力,使我們的設(shè)備更加的柔性。 在很多場(chǎng)合,單靠單機(jī)的控制是無(wú)法保證設(shè)備的順暢運(yùn)行,而通過(guò)設(shè)備與設(shè)備的信息交流達(dá)到我們想要的效果。單工位的意義也就是說(shuō)兩者之間,一個(gè)只能發(fā)送,而一個(gè)只能接收,比如一個(gè)特務(wù)他只能接收上司的指示,而無(wú)法給上司回復(fù);半雙工位也就是兩個(gè)能都能發(fā)送和接受數(shù)據(jù),但不能同時(shí)發(fā)送和接受,比如你打電話時(shí)是不能接電 話 ,對(duì)方也一樣;而全雙工位是兩者之間都能發(fā)送和接受數(shù)據(jù),并可同時(shí)發(fā)送和接受。串口速度比較慢,但只要兩條或者三條口線就能解決問(wèn)題,并能借用電話線來(lái)進(jìn)行遠(yuǎn)程控制。當(dāng)然中斷的級(jí)別根據(jù)各種 PLC 內(nèi)部 CPU 的資源有關(guān),同時(shí)也跟堆棧的容量大小也有關(guān)系。它在PLC 執(zhí)行程序時(shí)一旦發(fā)現(xiàn)高級(jí)計(jì)數(shù)器對(duì)應(yīng)的中斷,就會(huì)立即放下手上的工作。 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(yàn)中獲取了更多的知識(shí)和教訓(xùn),來(lái)不斷的發(fā)展 PLC技術(shù),將它推向更高浪潮。 你也許聽過(guò)太多的這個(gè)詞 :“死機(jī)”,大致的意思是 CPU 工作量過(guò)大,內(nèi)部資源不足等情況造成程序無(wú)法運(yùn)行。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(gè)小小的例子來(lái)說(shuō)明 . 每一個(gè)設(shè)備總是不會(huì)忘記有一個(gè)按鈕,它也是在我們遇到緊急情況時(shí)使用的,那就是急停按鈕。 很多的情況下我們總喜歡采用串并轉(zhuǎn)換芯片來(lái)進(jìn)行傳輸,這種情況下不需要我們進(jìn)行過(guò)于復(fù)雜的寄存器設(shè)置了,而直接通過(guò)數(shù)據(jù)傳送指令進(jìn)行數(shù)據(jù)交流,但在通信中并不是一個(gè)十分可行的辦法,因?yàn)樵诎l(fā)送數(shù)據(jù)的時(shí)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。 信息輸送的過(guò)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(shí)數(shù)據(jù)線和時(shí)鐘線是同步的,也就是數(shù)據(jù)信號(hào)和時(shí)鐘信號(hào)同時(shí)由 CPU 進(jìn)行發(fā)送,這需要彼此都要專門的時(shí)鐘信號(hào)來(lái)進(jìn)行傳送和接送,并且是強(qiáng)制性的,這種方法的特點(diǎn)在于它的速度極快、但相應(yīng)占用 CPU 的工作時(shí)間也相對(duì)的要長(zhǎng)、同時(shí)技術(shù)難度也非常的大。這樣通過(guò)信息共享來(lái)使得兩者之間鏈接起來(lái),形成一個(gè)共體,從而使的兩者間的配合更加的緊 密,在彼此間達(dá)到映影相揮的效果。 以上僅僅是 PLC 的優(yōu)點(diǎn)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(guò)大的甚至是致命的失誤是我們無(wú)法容忍的。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。 But take data in the watch for an instruction procedure that controls the PLC, that had the difficulty very much, for example you have to control one pedestal robot to press the action work that you imagine, you will draw up for it the form that a procedure bine with the data sends out to pass by. The form that information transport contain single work, the half a work and the difference of a workses .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。附錄 外文資料 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 more strong。And the PLC