【正文】 box carefully sweeping health。 (3) Maintenance scheduling and operator contact before and well, be linked to overhaul licensing office hung maintenance card。 (4) Connected to the power supply rack power cord clear line number keep in mind and remove the link location, then remove the power rack and rack screws connected, power rack can be removed。(3) RAM module to remove or insert the CPU from th。 (6) Installed in reverse order。 (2) The way the CPU on the front panel select switch from the Run to Stop position。3. Maintenance preparation, maintenance of order(1) Ready before maintenance tools。 PLC ConnectionsWhen a process is controlled by a PLC it uses inputs from sensors to make decisions and update outputs to drive actuators, as shown in Figure . The process is a real process that will change over time. Actuators will drive the system to new states (or modes of operation). This means that the controller is limited by the sensors available, if an input is not available, the controller will have no way to detect a condition.The control loop is a continuous cycle of the PLC reading inputs, solving the ladder logic, and then changing the outputs. Like any puter this does not happen instantly. Figure shows the basic operation cycle of a PLC. When power is turned on initially the PLC does a quick sanity check to ensure that the hardware is working properly. If there is a problem the PLC will halt and indicate there is an error. For example, if the PLC backup battery is low and power was lost, the memory will be corrupt and this will result in a fault. If the PLC passes the sanity checks it will then scan (read) all the inputs. After the inputs values are stored in memory the ladder logic will be scanned (solved) using the stored values not the current values. This is done to prevent logic problems when inputs change during the ladder logic scan. After this the system goes back to do a sanity check, and the loop continues indefinitely. Unlike normal puters, the entire program will be run every scan. Typical times for each of the stages are in the order of milliseconds.Questions Should Pay Attention to When PLC Is in the UsePLC which should pay attention to in the application is specially the control device which serves for the industrial production, usually does not need to take any measure, may use directly in the industry environment. But, when the production environment is too bad, the electromagnetic interference is special intense, or installs uses improper, cannot guarantee PLC the normal operation, therefore should pay attention to the following questions in the use. First, Siemens PLC maintenance 1. Maintenance procedures, equipment, periodic testing, adjustment provisions (1) Halfyearly or quarterly inspection PLC cabinet terminal connections, and if time to reloose strong local connection。 if it is 0 the output will be turned off. The ladder logic program in Figure , is equivalent to the mnemonic program. Even if you have programmed a PLC with ladder logic, it will be converted to mnemonic form before being used by the PLC. In the past mnemonic programming was the most mon, but now it is unmon for users to even see mnemonic programs. Sequential Function Charts (SFC) have been developed to acmodate the programming of more advanced systems. These are similar to flowcharts, but much more powerful. The example seen in Figure is doing two different things. To read the chart, start at the top where is says start. Below this there is the double horizontal line that says follow both paths. As a result the PLC will start to follow the branch on the left and right hand sides separately and simultaneously. On the left there are two functions the first one is the power up function. This function will run until it decides it is done, and the power down function will e after. On the right hand side is the flash function。黃北剛. 工廠電氣控制電路實(shí)例詳解. 北京: 化學(xué)工業(yè)出版社, 總之，這此的設(shè)計(jì)教會(huì)了我很多，不僅僅是專業(yè)知識(shí)得到擴(kuò)展，更多的是發(fā)現(xiàn)問(wèn)題，解決問(wèn)題的能力和獲取知識(shí)的能力得到鍛煉。在此，我鄭重的向在此過(guò)程中給予我?guī)椭睦蠋熀屯瑢W(xué)們表達(dá)深深的謝意，同時(shí)也感謝學(xué)校能夠給我們提供這么好的實(shí)驗(yàn)條件，能讓我們不僅僅是在紙張上完成自己的課程設(shè)計(jì)，更是讓我們能親眼看見(jiàn)自己辛苦幾個(gè)月的設(shè)計(jì)成果。最終，在通過(guò)各方面的努力下，該電鍍生產(chǎn)線控制系統(tǒng)的設(shè)計(jì)基本完成，在設(shè)計(jì)當(dāng)中我充分考慮到了操作的方便性，工藝的簡(jiǎn)單性。結(jié)　論這次對(duì)電鍍生產(chǎn)線控制系統(tǒng)的設(shè)計(jì)讓我更多的了解到了電鍍這個(gè)工藝的發(fā)展前景，讓我重新認(rèn)識(shí)了用PLC來(lái)設(shè)計(jì)控制系統(tǒng)的使用價(jià)值。圖 56 連續(xù)工作左行系統(tǒng)左行到左限位，碰到左限開(kāi)關(guān)時(shí)，系統(tǒng)開(kāi)始下降向原位回歸，如圖57所示。圖52 連續(xù)工作上升按動(dòng)上限開(kāi)關(guān)，系統(tǒng)向右運(yùn)行，如圖53所示。第5章 系統(tǒng)軟硬件調(diào)試我們?cè)谠O(shè)計(jì)的最后階段把軟件和硬件結(jié)合起來(lái)，成功實(shí)現(xiàn)了電鍍生產(chǎn)線系統(tǒng)的監(jiān)控功能。至此，整個(gè)程序的組態(tài)軟件編寫(xiě)已經(jīng)完成，即可進(jìn)入下一個(gè)階段的工作。if(\\本站點(diǎn)\SS==1)\\本站點(diǎn)\SXYX=\\本站點(diǎn)\SXYX+20。另外，再輸入一些符號(hào)時(shí)須在中文方式下。按照上面的步驟，根據(jù)設(shè)計(jì)需求，分別對(duì)畫(huà)面中的物件進(jìn)行動(dòng)畫(huà)連接，從而實(shí)現(xiàn)了外部輸入量與內(nèi)部事物的數(shù)據(jù)連接。 動(dòng)畫(huà)連接在新畫(huà)面中雙擊需要連接的物件，彈出如圖415所示對(duì)話框。所以該軟件開(kāi)發(fā)了一種結(jié)構(gòu)變量的定義的方法，即可以有效地解決該問(wèn)題，又使軟件的工作效率大大的提高了。圖414 定義變量在變量類(lèi)型中選取變量類(lèi)型，一般的變量類(lèi)型有“內(nèi)存”和“IO”兩種類(lèi)型，在這兩種類(lèi)型中又分“離散、整數(shù)、實(shí)數(shù)、字符串形”。至于新建的設(shè)備相當(dāng)于一個(gè)中間裝置，它將實(shí)物PLC與自己建造的變量聯(lián)系起來(lái)，相當(dāng)于把程序與界面聯(lián)系了起來(lái)，為以后的控制做好了準(zhǔn)備。圖411 通信參數(shù)設(shè)置此步驟選擇系統(tǒng)默認(rèn)的值就可以，單擊“下一步”進(jìn)入如圖412所示設(shè)備配置參數(shù)信息總結(jié)。圖49 設(shè)備配置向?qū)еx擇COM1即可符合本設(shè)計(jì)和實(shí)驗(yàn)室設(shè)備要求。根據(jù)本設(shè)計(jì)要求，畫(huà)出本系統(tǒng)工作所需要圖畫(huà)，如圖46所示。 進(jìn)入新建的組態(tài)王工程，選中工程瀏覽器左側(cè)的畫(huà)面，在右側(cè)雙擊新建按鈕，則彈出如圖44所示對(duì)話框。 創(chuàng)建組態(tài)畫(huà)面進(jìn)入組態(tài)王開(kāi)發(fā)系統(tǒng)后，就可以為每個(gè)工程建立數(shù)目不限的畫(huà)面，在每個(gè)畫(huà)面上生成互相關(guān)聯(lián)的靜態(tài)或動(dòng)態(tài)圖形對(duì)象。單擊“下一步”繼續(xù)。圖41 工程向?qū)е粏螕簟跋乱徊健崩^續(xù)，會(huì)出現(xiàn)如圖42所示“新建工程向?qū)е睂?duì)話框。強(qiáng)大的腳本語(yǔ)言處理，能夠幫助你實(shí)現(xiàn)復(fù)雜的邏輯操作和與決策處理；全新的Web Server架構(gòu)，全面支持畫(huà)面發(fā)布、實(shí)時(shí)數(shù)據(jù)發(fā)布、歷史數(shù)據(jù)發(fā)布以及數(shù)據(jù)庫(kù)數(shù)據(jù)的發(fā)布；方便的配方處理功能。組態(tài)軟件的出現(xiàn)，把用戶從這些困境中解脫出來(lái)，可以利用組態(tài)軟件的功能，構(gòu)建一套最適合自己的應(yīng)用系統(tǒng)。第4章 系統(tǒng)組態(tài)畫(huà)面設(shè)計(jì) 組態(tài)軟件介紹組態(tài)軟件是指一些數(shù)據(jù)采集與過(guò)程控制的專用軟件，它們是在自動(dòng)控制系統(tǒng)監(jiān)控層一級(jí)的軟件平臺(tái)和開(kāi)發(fā)環(huán)境，使用靈活的組態(tài)方式，為用戶提供快速構(gòu)建工業(yè)自動(dòng)控制系統(tǒng)監(jiān)控功能的、通用層次的軟件工具[17]。圖32 程序梯形圖 指令表指令編程是另一種PLC編程方法，指令表也可以很容易從梯形圖得到，本設(shè)計(jì)具體指令表如下。編程過(guò)程中先解決連續(xù)工作和單周期工作的軟件編寫(xiě)，然后解決步進(jìn)工作方式的軟件編寫(xiě)，最終完成整個(gè)系統(tǒng)的程序。當(dāng)系統(tǒng)工作在連續(xù)狀態(tài)時(shí)，程序會(huì)按照設(shè)計(jì)不進(jìn)行計(jì)數(shù)，從而可以一直循環(huán)下去，達(dá)到連續(xù)工作的設(shè)計(jì)要求。由于掃描時(shí)間很短（一般不過(guò)幾十毫秒），所以控制效果同電氣控制電路是基本相同的。梯形圖中每個(gè)繼電器和觸點(diǎn)均為PLC存儲(chǔ)器中的一位，相應(yīng)位為“1”，表示繼電器線圈通電、常開(kāi)接點(diǎn)閉合或常閉接點(diǎn)斷開(kāi)；相應(yīng)位為“0”，表示繼電器線圈斷電、常開(kāi)接點(diǎn)斷開(kāi)或常閉接點(diǎn)閉合。梯形圖中的假想電流在圖中只能作單方向的流動(dòng)，即只能從左向右流動(dòng)。PLC梯形圖具有以下一些特點(diǎn)。我們?cè)诒敬卧O(shè)計(jì)中選擇梯形圖編程。 PLC編程語(yǔ)言PLC是通過(guò)運(yùn)行編寫(xiě)的用戶程序?qū)崿F(xiàn)控制任務(wù)的。同時(shí)在程序中其常開(kāi)觸點(diǎn)閉合，常閉觸點(diǎn)斷開(kāi)。3. 輸入繼電器：輸入繼電器一般都有一個(gè)PLC的輸入端子與之對(duì)應(yīng)，它用于接受外部的開(kāi)關(guān)信號(hào)。利用定時(shí)器的觸點(diǎn)就可以得到控制所需的延時(shí)時(shí)間。