【正文】 he internal memory, it is possible to control a pneumatic system that has a sequence with 48 steps if all the resources for all steps are used, but it is possible to reach sixty steps in the case of a simpler system. The programming of the controller does not use PLC languages, but a configuration that is simple and intuitive. With electropneumatic system, the programming follows the same technique that was used before to design the system, but here the designer work s directly with the states or steps of the system. With a very simple machine language the designer can define all the configuration of the step using four or five bytes. It depends only on his experience to use all the resources of the controller. The controller task is not to work in the same way as a mercial PLC but the purpose of it is to be an example of a versatile controller that is designed for a specific area. Because of that, it is not possible to say which one works better。 the most important of them is the parallel circuit linked with all the others steps. That circuit should be able to stop the sequence at any time and change the state of the actuators to a specific position. This kind of circuit can be used as a reset or emergency buttons. The next Figs. 7 and 8 show the result of using the method without the controller. These pictures are the electric diagram of the control circuit of the example, including sensors, buttons and the coils of the electrical valves. The auxiliary elements are included, like the automatic/manual switcher that permit a continuous work and the two start buttons that make the operator of a machine use their two hands to start the process, reducing the risk of accidents. 6. Changing the example to a user program In the previous chapter, the electropneumatic circuits were presented, used to begin the study of the requires to control a system that work with steps and must offer all the functional elements to be used in a real application. But, as explained above, using a PLC or this specific controller, the control bees easier and the plexity can be increase also. Table 2 shows a resume of the elements that are necessary to control the presented example. With the time diagram, the step sequence and the elements of the system described in Table 2 and Figs. 5 and 6 it is possible to create the configuration of the steps that can be sent to the controller (Tables 3 and 4). While using a conventional PLC, the user should pay attention to the logic of the circuit when drawing the electric diagram on the interface (Figs. 7 and 8), using the programmable controller, described in this work, the user must know only the concept o f the method and program only the configuration of each step. It means that, with a conventional PLC, the user must draw the relation between the lines and the draw makes it hard to differentiate the steps of the sequence. Normally, one needs to execute a simulation on the interface to find mistakes on the logic The new programming allows that the configuration of the steps be separated, like described by the method. The sequence is defined by itself and the steps are described only by the inputs and outputs for each step. The structure of the configuration follows the order: 1byte: features of the step。 一種 非常簡(jiǎn)單的機(jī)械語(yǔ)言能讓設(shè)計(jì)者用四或五個(gè)位元組定義步驟所有結(jié)構(gòu)構(gòu)成。 圖 9 A ,B 傳動(dòng)裝置和傳 感器 圖 10 C ,D 傳動(dòng)裝置和傳感器 表 5 表現(xiàn)的是使用系統(tǒng)如何被儲(chǔ)藏在控制器里 ,這在前文中也詳細(xì)說(shuō)明過(guò)。 表 2所示的是控制上面提到的系統(tǒng)的必需設(shè)施。他們中最重要的是連接在每一步驟中的平行線路。 圖 6 顯示了程序設(shè)計(jì)的第一部分。第一步，主動(dòng)器 A開(kāi)始運(yùn)行，并保持在一個(gè)特定的位置一直到一個(gè)循環(huán)的結(jié)束，如圖 5 所示它可以確定某一對(duì)象的下一運(yùn)動(dòng)。但是也可以設(shè)計(jì)一個(gè)程序 ,利用可視資源為使用者翻譯所需要的信息。 安全性 如果想正常運(yùn)行程序，必須保證每一個(gè)步驟都正確的執(zhí)行。在步驟的運(yùn)行過(guò)程中，程序自動(dòng)選擇如何讀取每一步驟的結(jié)構(gòu)。 這一個(gè)控制器以不同的方式工作 ,它讀取步驟的結(jié)構(gòu) ,等待輸入 ,然后升級(jí)或輸出，然后直接跳躍到下一個(gè)步驟，開(kāi)始另一次的程序運(yùn)行。我們把一個(gè)序列從輸入端輸入，經(jīng)過(guò)轉(zhuǎn)換后，由輸出端輸出。 圖 1 氣壓系統(tǒng)標(biāo)準(zhǔn)回路 圖 2 電控氣壓系統(tǒng)標(biāo)準(zhǔn)回路 第一步是為每個(gè)步驟設(shè)計(jì)那些種標(biāo)準(zhǔn)的線路。但是這種設(shè)計(jì)的主要優(yōu)點(diǎn)在于設(shè)計(jì)人員非常了解自己的控制器，可以自由掌握控制器的大小尺寸，改變它的功能。 市場(chǎng)上的許多家公司都使用了常規(guī)的 PLC，它不僅可以用氣流系統(tǒng)來(lái)控制，還可以用各種電氣設(shè)備。應(yīng)用于電氣系統(tǒng)的可編程序控制器 此項(xiàng)目主要是研究電氣系統(tǒng)以及簡(jiǎn)單有效的控制氣流發(fā)動(dòng)機(jī)的程序和氣流系統(tǒng)的狀態(tài)。 PLC 的用途廣泛，可以應(yīng)用于許多工業(yè)生產(chǎn)中，甚至用于建筑物的安全和自動(dòng)化系統(tǒng)中。這就意味著此項(xiàng)目有更多的獨(dú) 特性，但同時(shí)系統(tǒng)的控制也由它的設(shè)計(jì)者所控制。第二步是聯(lián)編標(biāo)準(zhǔn)的線路，最后一步是連接接收來(lái)自感應(yīng)器，開(kāi)關(guān)和先前的運(yùn)動(dòng)信號(hào)，同時(shí)把空氣或電傳送給每個(gè)步驟的補(bǔ)給線。 這些步驟的所有過(guò)程都是在微控制器內(nèi)部進(jìn)行的，并且以同樣的方式在運(yùn)行著。 它也有局限性，例如這種控制器有時(shí)會(huì)不執(zhí)行指令，在同一程序指令下，會(huì)出現(xiàn)某一個(gè)運(yùn)行的反復(fù)等等 ，但是這一個(gè)問(wèn)題可以通過(guò)外部的邏輯 運(yùn)行解決。這個(gè)操作有兩個(gè)位元組位于電 子輸入處。更重要的是，應(yīng)該有預(yù)防運(yùn)行故障和問(wèn)題的解決方法。 但是，如果想聯(lián)結(jié)電腦接口和控制器，至少應(yīng)該有一個(gè)儀器來(lái)保證數(shù)據(jù)的可靠性。第二步，當(dāng) A完成了它的工作后，主動(dòng)器 C連同 B一起開(kāi)始盡可能多的產(chǎn)生電流