1、浙江工業(yè)大學(xué)教科學(xué)院畢業(yè)設(shè)計(jì)外文資料翻譯設(shè)計(jì)題目： 龍門刨床刨臺(tái)運(yùn)動(dòng)模擬器的設(shè)計(jì) 學(xué)生姓名： 學(xué) 號(hào)： 專 業(yè)： 外文出處： HYPERLINK :/ springerlink /content/1865-0929/ o Link to the Book Series of this Chapter Communications in Computer and Information Science, 1, Volume 225, HYPERLINK :/ springerlink /content/978-3-642-23219-0/ o Link to the Book of this C

2、hapter Applied Informatics and Communication, Part 2, Pages 479-486指導(dǎo)教師： 2021年 2 月 12 日The Design and Application of Sewage TreatmentAutomation System Based on S7-300 PLCAbstract. For the demand of domestic sewage treatment in county-level city, a plan of Distributed Control System in municipal wast

3、ewater treatment automation system is proposed. The main function of which is to supervisory control each sub-system of municipal wastewater treatment via the configuration software WinCC, Siemens S7-300 PLC. The feature of the system is mainly as follows, collection of PLC data, protocol conversion

4、, the transmission of data through fiber, the realization of projects in configuration software, the real-time data storage in database and the release of each kind of report forms, curves, alarm events in display and so on. The idea of the system designation and the detailed characterization of the

5、 system are also presented in this paper.Keywords: sewage treatment, Distributed Control System, Siemens S7-300 PLC, WinCC Configuration software.IntroductionAlong with the rapid development of economy in China, environmental protection has been a prominent issue. Sewage Treatment is one of the most

6、 important parts of environmental protection. As the computer technology and sewage treatment technology developed rapidly, it is necessary to monitor the wastewater treatment process with advanced control technology and equipment.The sewage treatment project of Inner Mongolian Huhhot Tumd Left Bann

7、er is the typical project among the county-level city of Hohhot, using Cyclic Activated Sludge System (CASS) to treat wastewater. For this project, we designed a DCS system, whose control system is Siemens S7-300 PLC and monitoring software is Siemens WinCC 6.2.CASS ProcessCASS biochemical treatment

8、 system is a complex system of multi-parameter (such as liquid level, water quality, flow rate, pressure, etc.), multi-tasking (such as water-in, aeration, sedimentation, drainage, etc.), multi-equipment (such as water decanter, blower, regulator etc.). It is the core of the whole biochemical dispos

9、al system. The main reaction zone of CASS pool works according to “aeration, idle, sedimentation, and decanter cycle procedures. Among them, the control of dissolved oxygen in CASS pool, anaerobic segment and aerobic segment is the core.The Structure of Control SystemThe structure of automatic sewag

10、e treatment control system is centralized management and decentralized control. The control system employs the control method combined with remote automatic control, remote manual control and field automatic control.In order to ensure sewage treatment systems well running, the master station and sla

11、ve station of PLC are independent. If one of the sub-systems breaks down, it will not affect the normal running of other system devices. Even if the whole control system malfunctions, it also can adjust itself to field manual control mode in time to ensure the normal operation of the sewage treatmen

12、t system. The PC in the central control room uses the model of dual-redundant to realize real-time monitoring. Two servers standby each other to jointly perform monitoring tasks. If one server conk out, the other one can undertake the tasks, automatically ensure the system can continue to provide se

13、rvices in the case without manual intervention.Data CommunicationS7 series PLC communications network mainly includes the following: multi-point interface (MPI) protocol of data communi cations, PROFIBUS, industrial Ethernet, point-to-point connections, through AS-I process of communication. This pr

14、oject has PROFIBUS, used in industrial Ethernet, point-to-point connections.The communication between S7-300 and WinCCPLC and PC communicate with each other through industrial Ethernet, PLC transmit the data of real-time production to the real-time database of configuration software of PC via optica

15、l fiber. PC can monitor the field device from far away. Because the PLC selected in this system is CPU 315-2PN/DP, which has integrated PROFINET interface. Communication between S7-300 and WINCC uses TCP/IP network protocol. TCP/IP network protocol is a de facto standard about communication protocol

16、 in IT services. Although the response time is about 100 ms magnitude, for application of factory control, the response time is enough.The Communication between master station and slave station of PLCPLC master station uses Siemens S7-300 PLC. The PLC of ClO2 workshop uses Siemens S7-200 PLC; Commun

17、ication between master station and slave station of PLC uses Profibus. Profibus, is internationalized and open, do not depend on the standard fieldbus of equipment manufacturer. It is a fieldbus which is used for control of factory automation workshop-level and data communications, and control of fi

18、eld device-level. The transmission speed of Profibus is at 9600 bauds 1.2107 bauds, and when the main system startup, all devices connected to the general line should be set at the same speed. This can achieve the dispersed digital control and scene communications network from field device-level to

19、workshop-level, so as to provide a viable solution for factory to realize the comprehensive automation and field device intellectualized. The processor module of Siemens S7-300 PLC is CPU 315-2 PN/DP, which has its own Profibus interface. The S7-300 PLC Profibus network is used as the master station

20、, S7-200 PLC Profibus network is used as the slave station. S7-200 PLC has no Profibus communication interface itself, so it has to communicate with master station through EM277.The communication between PLC and power equipmentAccording to the design requirements, the communication between PLC and p

21、ower equipment need to be established, for the current, voltage and power in the power supply system should be monitored. Siemens PLC make the point-to-point communication link with the power equipment through the communication module CP341. The power equipment provides RS485 communication interface

22、 in half-duplex asynchronous serial communication, and uses MODBUS RTU communication protocol. MODBUS protocol is one of the network protocols in the industrial control unit. The control equipments produced by different manufacturers can be linked as industrial network by MODBUS protocol, and that e

23、quipments linked in the different networks can make the data communication. The MODBUS network can connect multiple equipments on one line, and each of the equipments can set communication address itself. Each controller can distinguish the devices by the address. Also, it decides what to do with th

24、e message send by the address. If response is needed, the controller will create feedback information and send it by MODBUS protocol. On the other network, there are frame and package constructs converted by the message in the MODBUS protocol. The conversion also extends the way to solve the problem

25、s such as address, routing paths and mistake detection in the specific network.Siemens S7-300 Hardware The S7-300 is a modular PLC. It consists of Rack, CPU Module; Signal Module, Function Module, Interface Module, Communications Processor, Power Module and Programming Module. The PLC system of the

26、project contains three racks, the main rack communicated with Expansion rack by IM360/361. The Phase I of Sewage Treatment Phase has 23 analog input points, 3 analog output points, 222 digital input points and 68 digital output points. In this PLC hardware configuration, 15% of all reserve margins i

27、s set aside, which is leaved for the phase II. The S7-300 PLC system hardware diagram is shown in Figure 3.Composition of PC Conitoring SystemThis paper takes the Chinese version WinCC 6.2 as systematic configuration software to realize the configuration function of superv ision appearance. It provi

28、des a variety of drivers for PLC, which makes the connection of PLC and PC much easier and the variable list configured in STEP7 can be us ed directly when connected with WinCC. The functional block diagram for PC monitor system is shown in Figure 4.“PC monitoring system functional description: 1) C

29、ontrol function : to realize the real-time control of the on-line device in the main control room, such as equipments start/stop, analog output regulation, PLC operating parameters setting online, etc. 2) Display function : to show the running state of the device being controlled via the graphics an

30、d animation, and display the real-time operating parameters of the field device. 3) Archive management: to set up a production database and save the original data of the production for calculation and analys is, according to the change speed, the importance of operating parameters, the r eal-time an

31、d historical running state. 4) Alarm function: to realize different alarm grades according to different needs, when an analog value (such as current, pressure, water level, concentration, etc.) measured exceed the given range, or a digital value (such as motor start/stop, valves on/off) is out of or

32、der. 5) Print function : to realize the real-time print of reports, graphics, various events and alarm. The print way can be divided into timed print, event trigger print and user-defined print. 6) Log management: to record the information for users to log in and out, in order to search the use inte

33、rval for different users. 7) Rights management: to set corresponding visit protection for different users, and prevent the users unauthorized to visit the monitor system.PLC Control ProgramThe system uses modular design to realize the program of PLC system via the STEP7 software. The program flow ch

34、art is shown in Figure 5.The control system adopts modularization program, and falls into 10 subprogram according to the workshop in the whole techni cal procedures. In the main program, it can call each subprogram in proper order. First, writting an analog acquisition subprogram in the orgnization

35、block 35, and the analog data will be refreshed every 100 millisecond. Then, the control program which is classified as remote manual control and remote auto control can switch through the bit flags between the two ways. Remote manual control can artificially control the devices start/stop, and remo

36、te auto control can automatically adjust the state of the device by the change of on-the-spot parameters. So the program can execute automatically and timely for every cycle, and all the devices can auto-stop to control when there are cascading failures. Modbus uses multi-site polling mode to commun

37、icate with power meters.ConclusionsThe automation system used in the sewage treatment is worthy of popularization, for it can meet the requirements of modern sewage treatment, reduce the day-to-day maintenance management, decrease the cost of sewage treatment, and ensure the operation and water qual

38、ity of effluent. With the development of engineering technology, the automation system in the sewage treatment plant will surely show its obvious advantages. The project was tested in 2021.10. The result turned out that the system is an advanced, reliable and simply operated control system, which ca

39、n better resolve some problems such as low automation, low reliability and large time delay and some other exist problems in the past sewage treatment.基于S7-300 PLC的污水處理自動(dòng)化系統(tǒng)的設(shè)計(jì)與應(yīng)用摘要. 在縣級(jí)城市生活污水處理的需求，集散控制系統(tǒng)在城市污水處理自動(dòng)化系統(tǒng)的方案提出的。其中的主要功能是通過組態(tài)軟件WinCC，西門子S7-300的城市污水處理的每個(gè)子系統(tǒng)的PLC監(jiān)控。該系統(tǒng)的功能主要有以下幾點(diǎn)，PLC的數(shù)據(jù)，協(xié)議轉(zhuǎn)換器，通

40、過光纖傳輸?shù)臄?shù)據(jù)的收集，工程，組態(tài)軟件實(shí)現(xiàn)實(shí)時(shí)數(shù)據(jù)存儲(chǔ)在數(shù)據(jù)庫(kù)和各種報(bào)告的發(fā)布形式，曲線顯示等報(bào)警事件。本文還提出了系統(tǒng)的系統(tǒng)名稱和詳細(xì)描述的想法。關(guān)鍵詞 污水處理系統(tǒng) 集散控制系統(tǒng) 西門子S7-300PLC WinCC組態(tài)軟件1 引言隨著中國(guó)經(jīng)濟(jì)的快速開展，環(huán)保一個(gè)突出的問題。污水處理是環(huán)境保護(hù)最重要的任務(wù)之一。隨著計(jì)算機(jī)技術(shù)和污水處理技術(shù)迅速開展，這是必要的監(jiān)控污水處理過程與先進(jìn)控制技術(shù)和設(shè)備。內(nèi)蒙古呼和浩特市土默特左旗的污水處理工程是典型工程在呼和浩特市的縣級(jí)市，采用循環(huán)式活性污泥系統(tǒng)系統(tǒng)CASS處理廢水。于這個(gè)工程，我們?cè)O(shè)計(jì)的DCS系統(tǒng)，其控制系統(tǒng)采用西門子S7-300 PLC的監(jiān)控軟

41、件是西門子WinCC6.2。2CASS工藝 CASS生化處理系統(tǒng)是一個(gè)復(fù)雜的系統(tǒng)多參數(shù)(如液位、水質(zhì)、流量、壓力等)、多任務(wù)(如水進(jìn)口,曝氣，沉淀，排水等，多設(shè)備如潷水器，風(fēng)機(jī)，穩(wěn)壓器等。它是整個(gè)生化處理系統(tǒng)的核心。CASS池主反響區(qū)的工程，按照“曝氣，閑置，沉淀，和潷水器“的循環(huán)過程。其中，控制溶解氧在CASS池，厭氧段和好氧段是核心。3控制系統(tǒng)的結(jié)構(gòu)自動(dòng)污水處理控制系統(tǒng)的結(jié)構(gòu)是集中管理和分散控制?？刂葡到y(tǒng)采用的控制方法結(jié)合遠(yuǎn)程自動(dòng)控制，遠(yuǎn)程手動(dòng)控制和領(lǐng)域的自動(dòng)控制。為了確保污水處理系統(tǒng)運(yùn)行，主站和PLC從站是獨(dú)立的。如果一個(gè)子系統(tǒng)發(fā)生故障，也不會(huì)影響其他系統(tǒng)設(shè)備的正常運(yùn)行。即使整個(gè)控制系統(tǒng)

42、出現(xiàn)故障，它也可以及時(shí)調(diào)整自己到現(xiàn)場(chǎng)手動(dòng)控制模式，以確保污水處理系統(tǒng)的正常運(yùn)行。在中央控制室的電腦采用雙冗余模式，以實(shí)現(xiàn)實(shí)時(shí)監(jiān)控。兩臺(tái)效勞器的待機(jī)彼此共同執(zhí)行監(jiān)測(cè)任務(wù)。如果一個(gè)效勞器發(fā)生故障了，其他人可以承當(dāng)?shù)娜蝿?wù)，自動(dòng)保證系統(tǒng)能繼續(xù)提供效勞無需人工干預(yù)的情況下。4數(shù)據(jù)通信S7系列PLC的通信網(wǎng)絡(luò)主要包括以下內(nèi)容：多點(diǎn)陽(yáng)離子數(shù)據(jù)通信接口MPI協(xié)議的PROFIBUS，工業(yè)以太網(wǎng)，點(diǎn)至點(diǎn)連接，通過AS-I的通信過程。這個(gè)工程有PROFIBUS總線，工業(yè)以太網(wǎng)，點(diǎn)至點(diǎn)連接。S7-300和WinCC之間的溝通PLC和PC機(jī)通過工業(yè)以太網(wǎng)相互通信，PLC的傳輸通過光纖到PC機(jī)的配置軟件的實(shí)時(shí)數(shù)據(jù)庫(kù)的實(shí)時(shí)

43、生產(chǎn)數(shù)據(jù)。PC可以監(jiān)視現(xiàn)場(chǎng)設(shè)備從很遠(yuǎn)的地方。因?yàn)镻LC在這個(gè)系統(tǒng)中選擇的是CPU315-2PN/DP，或已集成PROFINET接口。S7-300和WINCC之間的通信使用TCP / IP網(wǎng)絡(luò)協(xié)議。TCP/ IP網(wǎng)絡(luò)協(xié)議，是事實(shí)上的IT標(biāo)準(zhǔn)有關(guān)通信協(xié)議效勞。雖然響應(yīng)時(shí)間是100毫秒左右的幅度，為應(yīng)用工廠控制，響應(yīng)時(shí)間是足夠的。主站和從站PLC站之間的溝通PLC主站采用西門子S7-300PLC。PLC 的ClO2車間使用西門子S7-200PLC通信主站和從站PLC站之間采用PROFIBUS。PROFIBUS，國(guó)際化和開放的，不依賴于標(biāo)準(zhǔn)現(xiàn)場(chǎng)總線的設(shè)備制造商。這是一個(gè)用于控制工廠的現(xiàn)場(chǎng)總線自動(dòng)化車間

44、級(jí)和數(shù)據(jù)通信，并控制現(xiàn)場(chǎng)設(shè)備級(jí)。PROFIBUS傳輸速度為9600波特1.2107波特，當(dāng)主系統(tǒng)啟動(dòng)時(shí)，一般線連接到的所有設(shè)備應(yīng)設(shè)置在相同的速度。這可以實(shí)現(xiàn)分散的數(shù)字控制和現(xiàn)場(chǎng)通信網(wǎng)絡(luò)現(xiàn)場(chǎng)設(shè)備級(jí)，車間級(jí)到從而為工廠提供一個(gè)可行的解決方案實(shí)現(xiàn)全面的自動(dòng)化和智能化現(xiàn)場(chǎng)設(shè)備。處理器西門子S7-300PLC模塊，CPU 315-2PN / DP的，它有其自己的PROFIBUS接口。在S7-300PLCProfibus網(wǎng)絡(luò)作為主站，S7-200PLCProfibus網(wǎng)絡(luò)作為從站。S7-200PLC有沒有PROFIBUS通訊接口本身，因此它具有與主站通過EM277的通信。PLC之間的通信和電力設(shè)備根據(jù)設(shè)計(jì)

45、要求，PLC和權(quán)力之間的溝通需要建立的電流，電壓和功率，在電源設(shè)備應(yīng)監(jiān)測(cè)系統(tǒng)。西門子PLC的點(diǎn)至點(diǎn)的通信鏈路通過通訊模塊CP341的發(fā)電設(shè)備。電源設(shè)備提供了RS485半雙工異步串行通信接口通信，并采用MODBUS RTU通訊協(xié)議。MODBUS協(xié)議是在工業(yè)控制單元的網(wǎng)絡(luò)協(xié)議之一。由不同廠家生產(chǎn)的控制設(shè)備可以連接作為工業(yè)MODBUS協(xié)議，該設(shè)備在不同網(wǎng)絡(luò)中的網(wǎng)絡(luò)鏈接可以進(jìn)行數(shù)據(jù)通信。MODBUS網(wǎng)絡(luò)可以連接多個(gè)上一條線，每個(gè)設(shè)備的設(shè)備可以設(shè)置通訊地址本身。每個(gè)控制器可以區(qū)分設(shè)備的地址。此外，它發(fā)送什么消息由地址決定。如果需要回應(yīng)，控制器將建立信息反響和發(fā)送MODBUS協(xié)議。在另一個(gè)網(wǎng)絡(luò)，有轉(zhuǎn)換的M

46、ODBUS消息幀和封裝結(jié)構(gòu)協(xié)議。轉(zhuǎn)換也擴(kuò)展的方式來解決問題，如地址，路由路徑及錯(cuò)誤檢測(cè)在特定的網(wǎng)絡(luò)。5西門子S7-300硬件S7-300是一個(gè)模塊化的PLC。它由機(jī)架，CPU模塊，信號(hào)模塊，功能模塊，接口模塊，電源模塊和編程模塊，通信處理器。該工程的PLC系統(tǒng)包含三個(gè)機(jī)架，主要機(jī)架與擴(kuò)展機(jī)架IM360/361傳達(dá)。第一階段的污水治療階段有23個(gè)模擬輸入點(diǎn)，3個(gè)模擬量輸出點(diǎn)，222個(gè)數(shù)字輸入分和68個(gè)數(shù)字輸出點(diǎn)。在此PLC的硬件配置，15的所有儲(chǔ)藏的利潤(rùn)率是預(yù)留的，這是第二階段的闊葉。S7-300PLC系統(tǒng)硬件框圖如圖3所示。6 PCConitoring系統(tǒng)組成以中國(guó)版本的系統(tǒng)配置軟件實(shí)現(xiàn)，監(jiān)督

47、外觀配置功能。它提供了多種司機(jī)為PLC，使PLC與PC的連接更容易和在STEP7中配置的變量列表可以是我們教育署直接與WinCC連接時(shí)。電腦監(jiān)控系統(tǒng)的功能框圖如圖4所示。“電腦監(jiān)控系統(tǒng)的功能描述：1控制功能：主要實(shí)現(xiàn)實(shí)時(shí)控制的上線的設(shè)備控制室設(shè)備，如啟動(dòng)/停止，模擬輸出調(diào)節(jié)，PLC運(yùn)行在線等參數(shù)設(shè)置。2顯示功能：顯示設(shè)備的運(yùn)行狀態(tài)，通過控制圖形和動(dòng)畫，顯示該領(lǐng)域的實(shí)時(shí)運(yùn)行參數(shù)設(shè)備。3檔案管理：建立一個(gè)生產(chǎn)數(shù)據(jù)庫(kù)，并保存原始數(shù)據(jù)計(jì)算和分析產(chǎn)品的生產(chǎn)，根據(jù)變化的速度，運(yùn)行參數(shù)的重要性，在R的EAL時(shí)間和歷史的運(yùn)行狀態(tài)。4報(bào)警功能：實(shí)現(xiàn)不同的報(bào)警級(jí)別，根據(jù)不同的需求，當(dāng)模擬值如電流，壓力，水位，濃度

48、等測(cè)量超過給定的范圍內(nèi)，或數(shù)字值如電機(jī)啟動(dòng)/停止，閥門開/關(guān)的訂單。5打印功能：可實(shí)現(xiàn)實(shí)時(shí)打印報(bào)告，圖形，各種活動(dòng)并報(bào)警。定時(shí)打印，事件觸發(fā)打印和打印方式，可分為用戶定義的打印。6日志管理：記錄的信息，以便為用戶登錄和注銷搜索針對(duì)不同用戶的使用間隔。7權(quán)限管理：為不同的用戶設(shè)置相應(yīng)的訪問保護(hù)，防止未經(jīng)授權(quán)的用戶訪問的監(jiān)控系統(tǒng)。7 PLC的控制程序該系統(tǒng)采用模塊化設(shè)計(jì)，實(shí)現(xiàn)PLC控制系統(tǒng)的方案，通過在STEP7軟件。程序流程圖如圖5所示?？刂葡到y(tǒng)采用模塊化的程序，分成10子程序根據(jù)技術(shù)性CAL在整個(gè)程序的研討會(huì)。在主程序中，可以在正確的順序調(diào)用每個(gè)子程序。首先，寫一個(gè)模擬采集在組織塊35，子程序

49、和模擬數(shù)據(jù)將被刷新每100毫秒。然后，控制方案被列為遠(yuǎn)程手動(dòng)控制和遠(yuǎn)程自動(dòng)控制，可以通過兩種方式之間的切換標(biāo)志位。遠(yuǎn)程手動(dòng)控制，可以人為控制的設(shè)備的啟動(dòng)/停止，遠(yuǎn)程自動(dòng)控制可自動(dòng)調(diào)節(jié)設(shè)備的狀態(tài)，通過對(duì)現(xiàn)場(chǎng)的變化參數(shù)。所以程序可以自動(dòng)執(zhí)行，并及時(shí)為每個(gè)周期，所有的設(shè)備可以自動(dòng)停下來控制時(shí)有連鎖故障。MODBUS使用通信電源米多點(diǎn)輪詢模式。8結(jié)論在污水處理中使用的自動(dòng)化系統(tǒng)是值得推廣的，因?yàn)樗軡M足現(xiàn)代污水處理的要求，減少日常的一天維護(hù)管理，降低污水處理本錢，并確保運(yùn)行和出水的水質(zhì)。隨著工程的開展技術(shù)，在污水處理廠的自動(dòng)化系統(tǒng)必將顯示其明顯的優(yōu)勢(shì)。該工程進(jìn)行了測(cè)試于。結(jié)果竟然系統(tǒng)是一個(gè)先進(jìn)，可靠，

50、操作簡(jiǎn)單的控制系統(tǒng)，從而能夠更好地解決一些問題，如自動(dòng)化低，可靠性低，大量的時(shí)間延遲和其他一些在過去的污水處理存在問題。浙江工業(yè)大學(xué)教科學(xué)院畢業(yè)設(shè)計(jì)外文資料翻譯設(shè)計(jì)題目： 龍門刨床刨臺(tái)運(yùn)動(dòng)模擬器的設(shè)計(jì) 學(xué)生姓名： 學(xué) 號(hào)： 專 業(yè)： 外文出處： HYPERLINK :/ springerlink /content/1865-0929/ o Link to the Book Series of this Chapter Communications in Computer and Information Science, 1, Volume 216, HYPERLINK :/ springerl

51、ink /content/978-3-642-23344-9/ o Link to the Book of this Chapter Advances in Computer Science, Environment, Ecoinformatics, and Education, Pages 552-556 指導(dǎo)教師： 2021年 2 月 12 日Research on Virtual Experiment System on PLCEducation Based on Teaching MaterialsAbstract. This paper presents virtual models

52、 of virtual experiment system, which are employed in the process of education of programmable logic control-ler (PLC) programming. Within control laboratory, the virtual models appear as well-suited alternate to physical-mechanical or process control model, whose feasibility, in laboratory condition

53、s, is sometimes complicated. As we do both, the development and employment of virtual models, the paper includes ap-proach to virtual models development, description of some of them as well as our experience of their usage. At the end, the possibility of remote connection to laboratory equipment is

54、discussed.Keywords: Programmable logic controller (PLC), supervisory control and data acquisition (SCADA), Virtual Model, Mathematical Model.IntroductionModern automated systems typically use programmable logic controllers to orchestrate and coordinate the plants being automated. Clearly there is a

55、great need for engineers with strong skills and knowledge in this area. But there are many challenges in teaching PLC programming to students.Although the PLC is often covered in undergraduate automation courses, many educational institutions lack resources to help students to become proficient PLC

56、users 1. Disadvantages of traditional labs include the need for a qualified teacher, the demand on institutional space, time constraints on the students and on the safety problems, recurring maintenance, etc. Experimental laboratories, however, represent a significant investment of both funds and sp

57、ace, which schools may not be able to meet 2, 3. Technologies are needed to help instructors to make the most of limited resources. Luckily some of these can be solved by PLC simulation software. PLC simulation software can be divided into two categories which are Virtual PLC and Virtual Environment

58、. Virtual PLC is the emulation package for PLC programming software. Virtual PLC, used with corresponding controller, lets users run and debug the application code while at computer. The leading engineering companies usually provide the Virtual PLC. CX-Simulator is a tool that functions as a virtual

59、 Omron PLC. S7-PLCSIM allows users to simulate the operation of a Siemens S7 PLC and users can test control programs with S7-PLCSIM without connecting to S7 hardware. RSLogix Emulator 5000 is a software simulator for the Allen Bradley line of Logix 5000 controllers. But the customer has to purchase

60、the corresponding simulator software product of the same manufacturer in order to gain access to all functions and options of the PLC in real experiment. Virtual Environment is a functional ladder logic design and PLC simulation software program that incorporates the basic functions used in PLC ladd