【正文】 ct that this controller cannot execute, inside the program, movements that must be repeated for some time, but this problem can be solved with some external logic ponents. Another limitation is that the controller cannot be applied on systems that have no sequence. These limitations are a characteristic of the system that must be analyzed for each application. 4. Characteristics of the controller The controller is based on the MICROCHIP microcontroller PIC16F877 [6,7] with 40 pins, and it has all the resources needed for this project .It has enough pins for all the ponents, serial munication implemented in circuit, EEPROM memory to save all the configuration of the system and the sequence of steps. For the execution of the main program, it offers plete resources as timers and interruptions. The list of resources of the controller was created to explore all the capacity of the microcontroller to make it as plete as possible. During the step, the program chooses how to use the resources reading the configuration string of the step. This string has two bytes for digital inputs, one used as a mask and the other one used as a value expected. One byte is used to configure the outputs value. One bytes more is used for the internal timer , the analog input or timeout. The EEPROM memory inside is 256 bytes length that is enough to save the string of the steps, with this characteristic it is possible to save between 48 steps （ Table 1） . The controller () has also a display and some buttons that are used with an interactive menu to program the sequence of steps and other configurations. . Interaction ponents For the real application the controller must have some elements to interact with the final user and to offer a plete monitoring of the system resources that are available to the designer while creating the logic control of the pneumatic system (): ?Interactive mode of work。 2byte: mask for the inputs。 the system made with microcontroller is an alternative that works in a simple way. 。 4byte: value for the outputs。 the speed is regulated by a flowing control valve. It was the second step. B and C are examples of actuators working together, while B pushes an object slowly, C repeats its work for some time. When B reaches the final position, C stops immediately its cycle and es back to the initial position. The actuator D is a single acting one with spring return and works together with the back of C, it is the third step. D works making very fast forward and backward movement, just one time. Its backward movement is the fourth step. D could be a tool to make a hole on the object. When D reaches the initial position, A and B return too, it is the fifth step. Fig. 6 shows the first part of the designing process where all the movements of each step should be defined [2]. (A+) means that the actuator A moves to the advanced position and (A?) to the initial position. The movements that happen at the same time are joined together in the same step. The system has five steps. These two representations of the system (Figs. 5 and 6) together are enough to describe correctly all the sequence. With them is possible to design the whole control circuit with the necessary logic ponents. But till this time, it is not a plete system, because it is missing some auxiliary elements that are not included in this draws because they work in parallel with the main sequence. These auxiliary elements give more function to the circuit and are very important to the final application。總之，我們的這個(gè)系統(tǒng)是基于微控制器而設(shè)計(jì)，簡(jiǎn)單快捷。利用電氣系統(tǒng)，我們的項(xiàng)目應(yīng)用了相同的技術(shù)，但同時(shí)我們的設(shè)計(jì)更加直接。 (圖 11) 顯示了一個(gè)以微控制器為基礎(chǔ)的非常有用的可編程的控制器。 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)。使用這種可編程的控制器 ,使用者必須知道運(yùn)行方法的觀(guān)念并且規(guī)劃每個(gè)步驟的結(jié)構(gòu)。 表 2 所示的是控制上面提到的系統(tǒng)的必需設(shè)施。 這些照片是控制線(xiàn)路的電圖表 ,包括感應(yīng)器，控制鍵和電的活瓣卷。 他們中最重要的是連接在每一步驟中的平行線(xiàn)路。 圖 6 A ,B ,C ,D 傳動(dòng)裝置傳動(dòng)順序 圖 5 和 6 所表現(xiàn)的系統(tǒng)運(yùn)行清楚的描述了所有序列。 圖 6 顯示了程序設(shè)計(jì)的第一部分。利用回旋的電流工作的主動(dòng)器 D 連同 返回來(lái)的 C一起工作。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)。根據(jù)使用者的構(gòu)造 ,它能利用分流或暫停應(yīng)付緊急線(xiàn)路情況 來(lái)保證系統(tǒng)安全。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。有兩個(gè)輸 入端共同工作可以快速的運(yùn)行這些功能。 4． 2 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。 除了一個(gè)互動(dòng)菜單外，這種控制器還有一個(gè)控制臺(tái)和一些指令按鈕，他們一起控制各個(gè)步驟的運(yùn)行和連續(xù)性，也控制其他的一些裝置。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)。 這種 控制器以微集成電路微控制器 PIC16F877[6,7] 為基礎(chǔ) ,它擁有全部此次項(xiàng)目所需要的資源。 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。輸入端有二個(gè)位元組 ,輸出端有一個(gè)，其他結(jié)構(gòu)部分和附加功能步驟有兩個(gè)。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。 上述方法可以使發(fā)