可編程序控制器應(yīng)用試題答案及評(píng)分標(biāo)準(zhǔn) 第 1 頁(yè)（共 14 頁(yè)） 電大可編程控制器應(yīng)用期末復(fù)習(xí)模擬試卷及參考答案一、填空題（每空 2 分，共 30 分）1. PLC 的輸入/輸出繼電器采用 八 進(jìn)制進(jìn)行編號(hào)，其它所有軟元件均采用 十 進(jìn)制進(jìn)行編號(hào)。(八 十)2. PLC 的狀態(tài)元件中 (S2S9) 用于初始狀態(tài)。(S2S9)3. 描述 PLC 的主要技術(shù)指標(biāo)有 、 、 、 、 和特殊功能模塊六種。(I/O 總點(diǎn)數(shù) 存儲(chǔ)容量 掃描速度 內(nèi)部寄存器 編程語(yǔ)言與指令系統(tǒng))4. PLC 的輸出形式主要有 輸出、 輸出和 輸出三種。(繼電器 晶體管 晶閘管)5. 說(shuō)明下列指令意義。 MOV RST ORB LD (數(shù)據(jù)傳送指令 復(fù)位指令 串聯(lián)電路塊的并聯(lián)指令 取指令)6、可編程序控制器采用微處理器作為中央處理單元，可以對(duì) 進(jìn)行控制，也可以對(duì) 進(jìn)行控制。 (邏輯量 模擬量)7、PLC 具有邏輯運(yùn)算功能，能夠描述繼電器觸點(diǎn)的 和 等各種連接。(串聯(lián) 并聯(lián))8、PLC 具有 和 功能，完成對(duì)模擬量的控制與調(diào)節(jié)。(模數(shù)轉(zhuǎn)換（A/D 轉(zhuǎn)換） 數(shù)模轉(zhuǎn)換（D/A 轉(zhuǎn)換）9、按結(jié)構(gòu)形式分類，PLC 可分為 式和 式兩種。(整體式 模塊式)10、 模塊是可編程序控制器系統(tǒng)的運(yùn)算控制核心。(CPU)11、 是安裝可編程控制器各類模板的機(jī)架，可根據(jù)實(shí)際需要選擇。(導(dǎo)軌)12、 模板用于對(duì) PLC 內(nèi)部電路供電。(電源)13、 是用來(lái)將輸入端不同電壓或電流信號(hào)轉(zhuǎn)換成微處理器所能接收的低電平信號(hào)。(輸入電壓轉(zhuǎn)換)14、輸出電平轉(zhuǎn)換是用來(lái)將 控制的低電平信號(hào)轉(zhuǎn)換為控制設(shè)備所需的電壓或電流信號(hào)。(微處理器)15、 是在微處理器與 I/O 回路之間采用的防干擾措施。(電氣隔離)16、S7-300/S4-400 可以通過(guò) 接口組成 PLC 網(wǎng)絡(luò)。多點(diǎn)接口（MPI）17、MPI 是 的簡(jiǎn)稱，MPI 網(wǎng)采用 的通信模式。 （多點(diǎn)接口 全局?jǐn)?shù)據(jù)（或 GD） ）18、全局?jǐn)?shù)據(jù)（GD）通信方式以 分支網(wǎng)為基礎(chǔ)，是為循環(huán)的傳送少量數(shù)據(jù)而設(shè)計(jì)的。 （多點(diǎn)接口（MPI） ）19、 通信方式以 MPI 分支網(wǎng)為基礎(chǔ)，是為循環(huán)的傳送少量數(shù)據(jù)而設(shè)計(jì)的。 （全局?jǐn)?shù)據(jù)（或 GD） ）20、可編程序控制器系統(tǒng)中，主站之間的通信方式為 ，主站與從站之間為 ，以及這兩種方式的混合。 （令牌方式 主從方式）21、PROFIBUS 網(wǎng)絡(luò)由 、從站、 等構(gòu)成。 （主站 網(wǎng)絡(luò)部件）22、DCS 是 的簡(jiǎn)稱，由單回路儀表控制系統(tǒng)發(fā)展起來(lái)。 （集散控制系統(tǒng)）二、簡(jiǎn)答題（每小題 5 分，共 20 分）1. 簡(jiǎn)述 PLC 的硬件結(jié)構(gòu)和軟件系統(tǒng)1.答： PLC 采用了典型的計(jì)算機(jī)結(jié)構(gòu)，硬件主要由微處理器（CPU） 、存儲(chǔ)器、采用掃描工作方式的 I/O 接口電路和電源等組成。PLC 的軟件系統(tǒng)由系統(tǒng)程序和應(yīng)用程序組成。2. 什么叫掃描工作方式？什么叫掃描周期？它主要受哪些影響？2. 答：與其它計(jì)算機(jī)系統(tǒng)一樣，PLC 的 CPU 是采用分時(shí)操作的原理，每一時(shí)刻執(zhí)行一個(gè)操作，隨著時(shí)間的延伸一個(gè)動(dòng)作接一個(gè)動(dòng)作順序地進(jìn)行。這種分時(shí)操作進(jìn)程稱為CPU 對(duì)程序的掃描。PLC 的用戶程序由若干條指令組成，指令在存儲(chǔ)器中按序號(hào)順序排列。CPU 從第一條指令開(kāi)始，順序逐條地執(zhí)行用戶程序，直到用戶程序結(jié)束。然后，返回第一條指令開(kāi)始新的一輪掃描，這就是 PLC 的掃描工作方式。除了執(zhí)行用戶程序之外，在每次掃描過(guò)程中還要完成輸入、輸出處理等工作。掃描一次所用的時(shí)間稱為掃描周期。掃描周期的長(zhǎng)短，首先與每條指令執(zhí)行時(shí)間長(zhǎng)短有關(guān)，其次與指令類型及包含指令條數(shù)的多少有關(guān)。3. 可編程控制器梯形圖編程規(guī)則的主要內(nèi)容是什么？3. 答：梯形圖程序編程的基本原則包括：（1）梯形圖中的階梯都是始于左母線終于右母線。（2）接點(diǎn)應(yīng)畫(huà)在水平線上，不要畫(huà)在垂直線上。（3）并聯(lián)塊串聯(lián)時(shí)，應(yīng)將接點(diǎn)多的支路放在梯形圖的左方。串聯(lián)塊并聯(lián)時(shí)，應(yīng)將接點(diǎn)多的并聯(lián)支路放在梯形圖的上方。（4）不宜使用雙線圈輸出?？删幊绦蚩刂破鲬?yīng)用試題答案及評(píng)分標(biāo)準(zhǔn) 第 2 頁(yè)（共 14 頁(yè)） 4. 為什么稱 PLC 的內(nèi)部繼電器為軟繼電器？和硬件繼電器相比，軟繼電器的觸點(diǎn)在使用上有何特點(diǎn)？ 4. 答：PLC 內(nèi)部的繼電器并不是實(shí)際的硬繼電器，而是 PLC 內(nèi)部的存儲(chǔ)單元。因此，稱為“軟繼電器” ，梯形圖是由這些“軟繼電器”組成的梯形圖控制線路圖，它們并不是真正的物理連接，而是邏輯關(guān)系的連接，稱為“軟連接” 。當(dāng)存儲(chǔ)單元某位狀態(tài)為 1 時(shí)，相當(dāng)于某個(gè)繼電器線圈得電；當(dāng)該位狀態(tài)為 0 時(shí)，相當(dāng)于該繼電器線圈斷電。軟繼電器的常開(kāi)觸點(diǎn)、常閉觸點(diǎn)可以在程序中使用無(wú)數(shù)多次5、傳統(tǒng)繼電器接觸器控制系統(tǒng)和可編程控制系統(tǒng)有何區(qū)別？答：傳統(tǒng)繼電器接觸器控制系統(tǒng)為“硬接線”程序控制系統(tǒng)，通過(guò)修改控制器件和接線來(lái)改變控制功能；可編程控制系統(tǒng)為“軟接線”程序控制系統(tǒng)，通過(guò)修改 PLC 程序并改動(dòng)少量接線端子來(lái)改變控制功能。6、簡(jiǎn)述可編程控制器的特點(diǎn)。 答：高可靠性，應(yīng)用靈活，編程簡(jiǎn)單，但價(jià)格較高。 （詳細(xì)解答也可）7、可編程控制器的性能指標(biāo)有哪些？ 答：衡量 PLC 的性能指標(biāo)分為硬件指標(biāo)和軟件指標(biāo)。硬件指標(biāo)包括環(huán)境溫度、濕度、抗干擾能力、使用環(huán)境和輸入輸出特性等；軟件指標(biāo)包括掃描速度、存儲(chǔ)容量、指令功能和編程語(yǔ)言等。8、可編程控制系統(tǒng)與工業(yè)控制計(jì)算機(jī)、集散控制系統(tǒng)的主要區(qū)別在哪些？答：工業(yè)控制計(jì)算機(jī)適用于要求快速、實(shí)時(shí)性強(qiáng)、模型復(fù)雜、計(jì)算工作量大的工業(yè)對(duì)象的控制；集散控制系統(tǒng)在模擬量處理和回路調(diào)節(jié)方面具有優(yōu)勢(shì)，主要側(cè)重于回路調(diào)節(jié)功能；可編程控制系統(tǒng)在數(shù)字處理和順序控制方面具有優(yōu)勢(shì)，主要側(cè)重于開(kāi)關(guān)量順序控制，具有很高的可靠性和抗干擾性。9、簡(jiǎn)述可編程控制器的基本結(jié)構(gòu)及其各部分功能。答：（1）導(dǎo)軌：安裝 PLC 各類模塊的機(jī)架；（2）電源模塊：用于對(duì) PLC 供電；（3）CPU 模塊：CPU 模塊為系統(tǒng)的運(yùn)算控制核心，根據(jù)系統(tǒng)的程序要求接收并存儲(chǔ)用戶程序和數(shù)據(jù)、現(xiàn)場(chǎng)輸入設(shè)備的狀態(tài)和參數(shù)，診斷 PLC 內(nèi)部電路工作狀態(tài)和編程過(guò)程中的語(yǔ)法錯(cuò)誤，完成用戶程序規(guī)定的運(yùn)算任務(wù)，更新有關(guān)標(biāo)志位的狀態(tài)和輸出狀態(tài)寄存器的狀態(tài)，實(shí)現(xiàn)輸出控制和數(shù)據(jù)通信等功能；（4）輸入輸出模板：連接 CPU 模板與現(xiàn)場(chǎng)輸入輸出元件或設(shè)備。10、PLC 配置電氣隔離的作用是什么？ 答：電氣隔離是在微處理器與 I/O 回路之間采用的防干擾措施。11、西門(mén)子（SIEMENS）公司有哪些主要系列的 PLC 產(chǎn)品？可以采用哪幾種編程語(yǔ)言？答：西門(mén)子（SIEMENS）公司主要的 PLC 產(chǎn)品有早期的 S3 系列、S5 系列和當(dāng)前的 S7 系列。S7 系列可采用的編程語(yǔ)言如下：（1）梯形圖（LAD） ；（2）語(yǔ)句表（STL） ；（3）功能塊圖/邏輯功能圖（FBD） ；（4）標(biāo)準(zhǔn)控制語(yǔ)言（SCL） ；（5）順序控制（S7-Graph） ；（6）連續(xù)功能圖（CFC） 。12、集散控制系統(tǒng)和可編程控制系統(tǒng)有何區(qū)別？ 答：集散控制系統(tǒng)在模擬量處理和回路調(diào)節(jié)方面具有優(yōu)勢(shì)，主要側(cè)重于回路調(diào)節(jié)功能；可編程控制系統(tǒng)在數(shù)字處理和順序控制方面具有優(yōu)勢(shì)，主要側(cè)重于開(kāi)關(guān)量順序控制。13、工業(yè)控制計(jì)算機(jī)和可編程控制系統(tǒng)有何區(qū)別？ 答：工業(yè)控制計(jì)算機(jī)適用于要求快速、實(shí)時(shí)性強(qiáng)、模型復(fù)雜、計(jì)算工作量大的工業(yè)對(duì)象的控制；可編程控制系統(tǒng)具有很高的可靠性和抗干擾性。14、在 PLC 控制系統(tǒng)設(shè)計(jì)中最為重要的原則是什么？答：在 PLC 控制系統(tǒng)設(shè)計(jì)中最為重要的原則是滿足控制對(duì)象的控制要求、確?？刂葡到y(tǒng)的安全可靠性、簡(jiǎn)化系統(tǒng)結(jié)構(gòu)。三、請(qǐng)寫(xiě)出以下指令表對(duì)應(yīng)的梯形圖（每小題 8 分，共 16 分）1 LD X000OR Y001ANI X003ANI Y002OUT Y001LD X002OR Y002ANI X003可編程序控制器應(yīng)用試題答案及評(píng)分標(biāo)準(zhǔn) 第 3 頁(yè)（共 14 頁(yè)） ANI Y001OUT Y002END1.2. LD X000OR X001LD X002AND X003LDI X004AND X005ORBOR X006ANBOR X003OUT Y000END2. X000 X003 Y002Y001Y001Y001Y002X002 X003 Y002X000X001X002 X003X004 X005X006Y000可編程序控制器應(yīng)用試題答案及評(píng)分標(biāo)準(zhǔn) 第 4 頁(yè)（共 14 頁(yè)） 3.LD I0.1A I0.2AN I0.3= M0.0LDN I0.1O I0.2O I0.3A I0.4NOT= M0.1四、請(qǐng)寫(xiě)出以下梯形圖對(duì)應(yīng)的指令表（每小題 10 分，共 20 分）1.1 LDI X0 AND X1LD X2ANI X3ORBAND X4X003可編程序控制器應(yīng)用試題答案及評(píng)分標(biāo)準(zhǔn) 第 5 頁(yè)（共 14 頁(yè)） LDI X5AND X7LD X6ANI M3ORBANBANI X10AND X11OUT T0K100AND TOOUT Y222. LD X000SET S20STL S20OUT Y000LD X001SET S21STL S21OUT Y002LD X002SET S22STL S22OUT Y003LD X003SET S26STL S26可編程序控制器應(yīng)用試題答案及評(píng)分標(biāo)準(zhǔn) 第 6 頁(yè)（共 14 頁(yè)） OUT Y006LD X004OUT S213LDN M0.0A M0.1= Q4.1 LDN M0.0= Q4.24。LD M0.0 AN I0.1= M0.3A T5= Q0.0AN M0.4= Q0.15.LD I0.3A C20ON I0.1A I0.2= Q2.1 LDN I0.1A C20可編程序控制器應(yīng)用試題答案及評(píng)分標(biāo)準(zhǔn) 第 7 頁(yè)（共 14 頁(yè)） O I0.3AN I0.4= Q2.2五、計(jì)算題（共 14 分）1. 三菱電機(jī) FX2-40MR 基本單元，其輸入/輸出點(diǎn)數(shù)為 24/16，用戶程序?yàn)?1000 步基本指令，PLC 運(yùn)行時(shí)不連接上位計(jì)算機(jī)等外設(shè)。I/O 掃描速度為 0.03ms/8 點(diǎn)，用戶程序的掃描速度取 0.74s/步，自診斷所需時(shí)間設(shè)為 0.96ms，試計(jì)算一個(gè)掃描周期所需的時(shí)間為多少？1. 解：掃描 I/O 的時(shí)間：T1=0.03ms×40/8 點(diǎn)=0.15ms掃描程序的時(shí)間：T2=0.74s×1000 步=0.74ms自診斷的時(shí)間： T3=0.96ms通信的時(shí)間： T4=0掃描周期：T=T1+T2+T3+T4=（0.15+0.74+0.96）ms=1.85ms六、分析題1、某控制系統(tǒng)選用 CPU224，其中模擬量擴(kuò)展模塊以 2 字節(jié)遞增的方式來(lái)分配地址。請(qǐng)按表中介紹的模塊連接形式，填寫(xiě)模塊 1 和模塊 3 的地址分配。主機(jī) CPU224模塊 1 DI4/DO4DC24V模塊 2 DI8DC24V模塊 3 AI4/AO112 位模塊 4 DI4/DO4DC24V模塊 5AI4/AO112 位I0.0 Q0.0I0.1 Q0.1 I1.5 Q1.5I3.0I3.1I3.2I3.3I3.4I3.5I3.6I3.7Q3.0Q3.1Q3.2Q3.3Q3.4Q3.5Q3.6Q3.71.答案主機(jī) CPU224模塊 1 DI4/DO4DC24V模塊 2 DI8DC24V模塊 3 AI4/AO1模塊 4 DO8DC24V模塊 5AI4/AO1I0.0 Q0.0I0.1 Q0.1 I1.5 Q1.5I2.0 Q2.0I2.1 Q2.1I2.2 Q2.2I2.3 Q2.3I3.0I3.1I3.2I3.3I3.4I3.5I3.6I3.7AIW0 AQW0AIW2 AIW4 AIW6 Q3.0Q3.1Q3.2Q3.3Q3.4Q3.5Q3.6Q3.7AIW8 AQW2AIW10AIW12AIW142、某控制系統(tǒng)選用 CPU224，請(qǐng)按表中介紹的模塊連接形式，填寫(xiě)模塊 1、模塊 3 和模塊 4 的地址分配。可編程序控制器應(yīng)用試題答案及評(píng)分標(biāo)準(zhǔn) 第 8 頁(yè)（共 14 頁(yè)） 主機(jī)CPU224模塊 1 EM221 DI8DC24V模塊 2 EM222 DO8DC24V模塊 3 EM235 AI4/AO112 位模塊 4 EM223 DI4/DO4DC24V模塊 5EM235 AI4/AO112 位I0.0 Q0.0I0.1 Q0.1 I1.5 Q1.1Q2.0Q2.1Q2.2Q2.3Q2.4Q2.5Q2.6Q2.7AIW8 AQW2AIW10AIW12AIW142.答案主機(jī) I/O 模塊 1I/O 模塊 2I/O 模塊 3I/O 模塊 4I/O 模塊 5I/OI0.0 Q0.0I0.1 Q0.1 I1.5 Q1.1I2.0I2.1I2.2I2.3I2.4I2.5I2.6I2.7Q2.0Q2.1Q2.2Q2.3Q2.4Q2.5Q2.6Q2.7AIW0 AQW0AIW2AIW4AIW6I3.0 Q3.0I3.1 Q3.1I3.2 Q3.2I3.3 Q3.3AIW8 AQW2AIW10AIW12AIW14六、設(shè)計(jì)題1、一臺(tái)三相異步電動(dòng)機(jī)正反轉(zhuǎn)控制的電路如下圖（a）所示；PLC 控制的接線如圖（b）所示。當(dāng)按下正向啟動(dòng)按鈕 SB1，電動(dòng)機(jī)正轉(zhuǎn)；當(dāng)按下反向啟動(dòng)按鈕 SB2，電動(dòng)機(jī)反轉(zhuǎn)；停機(jī)時(shí)按下停機(jī)按鈕 SB3。過(guò)載是熱繼電器 FR 動(dòng)作，電動(dòng)機(jī)停止。按照上述工作要求：（1）分配 I/O通道；（2）選擇 plc，畫(huà)出梯形圖。圖（a）電動(dòng)機(jī)正反轉(zhuǎn)控制電路 圖（b）PLC 控制接線圖1、(1) 表 電動(dòng)機(jī)正反轉(zhuǎn)控制電路 IO 分配表可編程序控制器應(yīng)用試題答案及評(píng)分標(biāo)準(zhǔn) 第 9 頁(yè)（共 14 頁(yè)） (2) 選西門(mén)子 S7-200 的 plc(也可以選其它型號(hào) plc)圖 電動(dòng)機(jī)正反轉(zhuǎn)控制電路的 PLC 控制程序2、兩臺(tái)電動(dòng)機(jī)的關(guān)聯(lián)控制：在某機(jī)械裝置上裝有兩臺(tái)電動(dòng)機(jī)。當(dāng)按下正向起動(dòng)按鈕 SB2，電動(dòng)機(jī)一正轉(zhuǎn)；當(dāng)按下反向起動(dòng)按鈕 SB3，電動(dòng)機(jī)一反轉(zhuǎn)；只有當(dāng)電動(dòng)機(jī)一運(yùn)行時(shí)，并按下起動(dòng)按鈕 SB4，電動(dòng)機(jī)二才能運(yùn)行，電動(dòng)機(jī)二為單向運(yùn)行；兩臺(tái)電動(dòng)機(jī)有同一個(gè)按鈕 SB1控制停止。按照上述工作要求：（1）分配 I/O 通道；（2）選擇 plc，畫(huà)出梯形圖。2、 （1）關(guān)聯(lián)控制功能的 I/O 分配表SB1 I0.0 總停按鈕，常閉觸點(diǎn)SB2 I0.1 電動(dòng)機(jī)一正轉(zhuǎn)起動(dòng)按鈕，常開(kāi)觸點(diǎn)SB3 I0.2 電動(dòng)機(jī)一反轉(zhuǎn)起動(dòng)按鈕，常開(kāi)觸點(diǎn)SB4 I0.3 電動(dòng)機(jī)二起動(dòng)按鈕，常開(kāi)觸點(diǎn)KM1 Q2.1 電動(dòng)機(jī)一正轉(zhuǎn)運(yùn)行KM2 Q2.2 電動(dòng)機(jī)一反轉(zhuǎn)運(yùn)行KM3 Q2.3 電動(dòng)機(jī)二運(yùn)行（2）選西門(mén)子 S7-200 的 plc(也可以選其它型號(hào) plc)可編程序控制器應(yīng)用試題答案及評(píng)分標(biāo)準(zhǔn) 第 10 頁(yè)（共 14 頁(yè)） 圖 電動(dòng)機(jī)關(guān)聯(lián)控制的 PLC 控制程序3、用接在輸入端的光電開(kāi)關(guān) SB1 檢測(cè)傳送帶上通過(guò)的產(chǎn)品，有產(chǎn)品通過(guò)時(shí) SB1 為常開(kāi)狀態(tài)，如果在 10s 內(nèi)沒(méi)有產(chǎn)品通過(guò)，由輸出電路發(fā)出報(bào)警信號(hào)，用外接的開(kāi)關(guān) SB2 解除報(bào)警信號(hào)。按照上述工作要求：（1）分配 I/O 通道；（2）選擇 plc，畫(huà)出梯形圖；（3）寫(xiě)出對(duì)應(yīng)的指令表程序。3、 （1）產(chǎn)品檢測(cè)控制電路 I/O 分配表SB1 I0.0 光電開(kāi)關(guān)，常開(kāi)觸點(diǎn)SB2 I0.1 解除報(bào)警開(kāi)關(guān)，常閉觸點(diǎn)Q0.0 報(bào)警信號(hào)T37 時(shí)間繼電器（2）選西門(mén)子 S7-200 的 plc(也可以選其它型號(hào) plc)圖 產(chǎn)品報(bào)警檢測(cè)的 PLC 控制程序4、下圖是小車自動(dòng)往返運(yùn)動(dòng)的主電路和繼電器控制電路圖。其中 KMl 和 KM2 分別是控制正轉(zhuǎn)運(yùn)行和反轉(zhuǎn)運(yùn)行的交流接觸器。用 KMl 和 KM2的主觸點(diǎn)改變進(jìn)入電機(jī)的三相電源的相序，即可改變電動(dòng)機(jī)的旋轉(zhuǎn)方向。圖中的 FR 是熱繼電器，在電動(dòng)機(jī)過(guò)載時(shí)，它的常閉觸點(diǎn)斷開(kāi)，使KMl 和 KM2 的線圈斷電，電動(dòng)機(jī)停轉(zhuǎn)。工作時(shí)，按下右行起動(dòng)按鈕 SB2 或左行起動(dòng)按鈕 SB3 后，要求小車在左限位開(kāi)關(guān) SQ1 和右限位開(kāi)關(guān)SQ2 之間不停的循環(huán)往返，直到按下停止按鈕 SB1。按照上述工作要求：（1）分配 I/O 通道；（2）選擇 plc，畫(huà)出梯形圖。可編程序控制器應(yīng)用試題答案及評(píng)分標(biāo)準(zhǔn) 第 11 頁(yè)（共 14 頁(yè)） 圖 小車自動(dòng)往返運(yùn)動(dòng)的繼電器控制電路圖4、 （1）小車自動(dòng)往返運(yùn)動(dòng)控制電路 I/O 分配表SB1 I0.2 停止按鈕，常閉觸點(diǎn)SB2 I0.0 右行起動(dòng)按鈕，常開(kāi)觸點(diǎn)SB3 I0.1 左行起動(dòng)按鈕，常開(kāi)觸點(diǎn)SQ1 I0.3 左限位開(kāi)關(guān)，常開(kāi)觸點(diǎn)SQ2 I0.4 右限位開(kāi)關(guān)，常開(kāi)觸點(diǎn)FR I0.5 熱保護(hù)，常閉觸點(diǎn)KM1 Q0.0 正轉(zhuǎn)運(yùn)行KM2 Q0.1 反轉(zhuǎn)運(yùn)行（2）選西門(mén)子 S7-200 的 plc(也可以選其它型號(hào) plc)圖 電動(dòng)機(jī)正反轉(zhuǎn)控制電路的 PLC 控制程序可編程序控制器應(yīng)用試題答案及評(píng)分標(biāo)準(zhǔn) 第 12 頁(yè)（共 14 頁(yè)） 5、由兩臺(tái)三相交流電動(dòng)機(jī) M1、M 2組成的控制系統(tǒng)的工作工程為：當(dāng)按下起動(dòng)按鈕 SB1電動(dòng)機(jī) M1起動(dòng)工作；延時(shí) 5s 后，電動(dòng)機(jī) M2起動(dòng)工作；當(dāng)按下停止按鈕 SB2，兩臺(tái)電動(dòng)機(jī)同時(shí)停機(jī)；若電動(dòng)機(jī) M1過(guò)載，兩臺(tái)電動(dòng)機(jī)同時(shí)停機(jī)；若電動(dòng)機(jī) M2過(guò)載，則電動(dòng)機(jī) M2停機(jī)而電動(dòng)機(jī) M1不停機(jī)。按照上述工作要求：（1）分配 I/O 通道；（2）選擇 plc，畫(huà)出梯形圖。5、 （1）電動(dòng)機(jī)控制的 I/O 分配表SB1 I0.0 起動(dòng)按鈕，常開(kāi)觸點(diǎn)SB2 I0.1 停機(jī)按鈕，常閉觸點(diǎn)FR1 I0.2 電動(dòng)機(jī) M1熱保護(hù)，常閉觸點(diǎn)FR2 I0.3 電動(dòng)機(jī) M2熱保護(hù)，常閉觸點(diǎn)KM1 Q2.1 電動(dòng)機(jī) M1運(yùn)行KM2 Q2.2 電動(dòng)機(jī) M2運(yùn)行T38 時(shí)間繼電器（2）選西門(mén)子 S7-200 的 plc(也可以選其它型號(hào) plc)可編程序控制器應(yīng)用試題答案及評(píng)分標(biāo)準(zhǔn) 第 13 頁(yè)（共 14 頁(yè)） 請(qǐng)您刪除一下內(nèi)容，O(_)O 謝謝！ 2015 年中央電大期末復(fù)習(xí)考試小抄大全，電大期末考試必備小抄，電大考試必過(guò)小抄 Many people have the same mixed feelings when planning a trip during Golden Week. With heaps of time, the seven-day Chinese 請(qǐng)您刪除一下內(nèi)容，O(_)O 謝謝！National Day holiday could be the best occasion to enjoy a destination. However, it can also be the easiest way to ruin how you feel about a place and you may become more fatigued after the holiday, due to battling the large crowds. During peak season, a dream about a place can turn to nightmare without careful planning, especially if you travel with children and older people. As most Chinese people will take the holiday to visit domestic tourist destinations, crowds and busy traffic are inevitable at most places. Also to be expected are increasing transport and accommodation prices, with the possibility that there will be no rooms available. It is also common that you' ll wait in the line for one hour to get a ticket, and another two hours at the site, to only see a tiny bit of the place due to the crowds. Last year, 428 million tourists traveled in China over the week-long holiday in October. Traveling during this period is a matter that needs thorough preparation. If you are short on time to plan the upcoming "Golden Week" it may not be a bad idea to avoid some of the most crowded places for now. There is always a place so fascinating that everyone yearns for. Arxan is a place like this. The beauty of Arxan is everlasting regardless of the changing of four seasons. Bestowed by nature, its spectacular seasonal landscape and mountains are just beyond word. Arxan is a crucial destination for the recommended travelling route, "China Inner Mongolia Arxan Hailar Manzhouli". It is also the joint of the four prairies across the Sino-Mongolian border, where people gravitate towards the exotic atmosphere mixed with Chinese, Russian, and Mongolia elements. As a historic site for the Yitian Battle, Arxan still embodies the spirit of Genghis Khan. Walking into Arxan, you will be amazed by a kaleidoscope of gorgeous colors all the year round - the Spring azaleas blooming red in the snow, the Summer sea wavering blue in the breeze, the Autumn leaves painted in yellow covering volcanic traces, and the Winter woods shining white on the vast alpine snowscape. Hinggan League Arxan city is situated in the far eastern area of Inner Mongolia Autonomous Region. Its full name "Haren Arxan" means "hot holy water" in the Mongolian language. Arxan is a tourism city in the northern frontier with a blend of large forest, grand prairies, vast snowfield, heaven lake cluster, thermium, as well as volcanic cluster. It is a rare and unique ecotourism base filled with healthy sunshine, clean air and unspoiled green. Nestled close to the country's largest virgin forest, and known for its spring and ecological environment, Arxan is marveled at by many tourists as the purest land on earth. You cannot miss out the Autumn of Arxan. It is definitely the best with brightly-colored scenery full of emotions. Autumn in the northern part of the country comes earlier than the South. A September rain followed by the footprints of Autumn brings more colors to the once emerald green mountain and blooming grassland. Shutterbugs flock to see for themselves the marvel of splendid colors around the mountains and waters, many of whom have travel a long distance and even camp here only to capture a moment of the nature wonder. The silver birch turns golden, while the larch is still proudly green. You will find yourself drowned in the intoxicating red of the wild fruits as well as the glamour of flowers in full blown. And your heart will be lingering on the woods as it's time for the wild fruits to ripe. The picturesque Arxan in Autumn is indeed a fairyland only exists in a dream that satisfies all your fantasies. If it rains heavily on Saturday night, some elderly Chinese will say it is because Zhinu, or the Weaving Maid, is crying on the day she met her husband Niulang, or the Cowherd, on the Milky Way. Most Chinese remember being told this romantic tragedy when they were children on Qixi, or the Seventh Night Festival, which falls on the seventh day of the seventh lunar month, which is usually in early August. This year it falls on Saturday, August 2. Folklore Story As the story goes, once there was a cowherd, Niulang, who lived with his elder brother and sister-in-law. But she disliked and abused him, and the boy was forced to leave home with only an old cow for company. The cow, however, was a former god who had violated imperial rules and was sent to earth in bovine form. One day the cow led Niulang to a lake where fairies took a bath on earth. Among them was Zhinu, the most beautiful fairy and a skilled seamstress. The two fell in love at first sight and were soon married. They had a son and daughter and their happy life was held up as an example for hundreds of years in China. Yet in the eyes of the Jade Emperor, the Supreme Deity in Taoism, marriage between a mortal and fairy was strictly forbidden. He ordered the heaven troop to catch Zhinu back. Niulang grew desperate when he discovered Zhinu had been taken back to heaven. Driven by Niulang's misery, the cow told him to turn its hide into a pair of shoes after it died. The magic shoes whisked Niulang, who carried his two children in baskets strung from a shoulder pole, off on a chase after the empress. The pursuit enraged the empress, who took her hairpin and slashed it across the sky creating the Milky Way which separated husband from wife. But all was not lost as magpies, moved by their love and devotion, formed a bridge across the Milky Way to reunite the family. Even the Jade Emperor was touched, and allowed Niulang and Zhinu to meet once a year on the seventh night of the seventh month. This is how Qixi came to be. The festival can be traced back to the Han Dynasty (206 BC-AD 220). Traditionally, people would look up at the sky and find a bright star in the constellation Aquila as well as the star Vega, which are identified as Niulang and Zhinu. The two stars shine on opposite sides of the Milky Way. Customs In bygone days, Qixi was not only a special day for lovers, but also for girls. It is also known as the "Begging for Skills Festival" or "Daughters' Festival." In this day, girls will throw a sewing needle into a bowl full of water on the night of Qixi as a test of embroidery skills. If the needle floats on top of the water instead of sinking, it proves the girl is a skilled embroiders. Single women also pray for finding a good husband in the future. And the newly married women pray to become pregnant quickly. Tradition transformed The love story of Niulang and Zhinu, and the Qixi Festival have been handed down for generations. Yet these ancient traditions and customs are slowly dying out. Many modern Chinese, particularly youngsters, seem to know more about St Valentine's Day on February 14, characterized by bouquets of roses, chocolates and romantic candlelight dinners, than they do about their home-grown day for lovers. Even Qixi is nowadays referred to as the "Chinese Valentine's Day." More and more young Chinese people begin to celebrate this day in a very similar way as that in western countries. Fewer people than ever will gaze at the heavens on Saturday to pick out the two stars shining bright on either side of the Milky Way, that is, if people even know on which day Qixi falls. There are ready reminders dotted about, in the form of big ads saying "Sales on Chinese Valentine's Day!" in shops, hotels and restaurants. But few young women will mark the festival with their boyfriends, or take part in traditional activities to pray for cleverness. A large-scale of exhibition on the Silk Road opened to the public in the National Museum on Thursday. The exhibition displays more than 400 treasures from Shaanxi province, Gansu province and 14 other regions. It is largest scale exhibition that shows the history of the Silk Road in recent years. As APEC is going on in Beijing, the exhibit aims to show the world this brilliant section of history. The Silk Road is a series of trade and cultural transmission routes that were central to cultural interaction through regions of the Asian continent. It connected the West and East by linking traders, merchants, pilgrims, monks, soldiers, nomads, and urban dwellers from China and India to the Mediterranean Sea during various periods of time. I met my dear hubby in 2009 the second year I was in my school and it was the first year when he came here. We became colleagues. And there was nothing special happening during that year. He was just a kind and humble brother graduated from the same college as me. But we did not know each other till he became my colleague and his office desk was just in front of me. There was only a glass between us. So actually we could see each other when we both look up. But it is not the main reason that really draws us close. How we become close to each other was something seems quite natural. We went out to play badminton with other colleagues and we sometimes chatted for a while. He is a man of few words but somehow sometimes will say something really humorous. Then one day, to my great surprise, I found a pot of beautiful flower on my desk. It was just the flower I had talked about with my colleague the other day, and I thought it was her who put the flower there. But the truth is not. It was the humble guy sitting in front of me. He just simply said ,”well, I caught sight of this flower and thought that its beautiful and you may like it”. I wonder why I was moved because of these simple words and present. Maybe it is the sincerity and the true self that impress me. I thanked him and some colleagues walked past my desk would appreciate the beautiful flower and they noticed that something romance happened there. Then later on, there were some little surprises once in a while. Once, there was something wrong with my drawer and I had complained about it unconsciously. And he fixed it for me. Then the other day, he placed several pink diamond roses beside the flower with a piece of paper saying” I love you more than I can say! Diamond stands for marriage, rose stand for love. I hope you are mine, become my wife. You are the only girl who I really want to spend the rest of my life to stand by.” Although there were some grammar errors but I got what he meant. He meant so clear and so direct. And actually, I accepted him some days earlier. I was just waiting for him to break the ice. So finally, the common interests and the common understanding brought us together. Some people say the relationship and the feeling will change after getting hitched. You will find that love is no longer strong and there is always lack of passion and whats worse you may find out many bad habits of your partner, which never appear when you are first in love before the marriage. It seems that many faults turn up after you truly living together and see each others face the moment you open your eyes in the early morning. But after almost 4 years from now, I do not feel any negative change in our relationship. During all these years, we know each other better and we become more tolerant about each other and I realize that if you really love a person you will accept his imperfect. And what is the qualification of a good husband? Once I was chatting with my colleague about this issue. And one of the qualifications I thought was that he must be a good cook. But to my surprise, my colleague said