【正文】 由于工業(yè)PLC無(wú)論何時(shí)不可能廣泛的涉及到MAP，生產(chǎn)廠家正在考慮專(zhuān)用網(wǎng)絡(luò)。如歐姆龍公司正在進(jìn)行一個(gè)有關(guān)MAP兼容性的項(xiàng)目。例如。然而，當(dāng)一個(gè)完整的生產(chǎn)自動(dòng)化協(xié)議說(shuō)明書(shū)沒(méi)有及時(shí)出現(xiàn)時(shí)許多公司都很失望。”通信和生產(chǎn)自動(dòng)化協(xié)議（MAP）通信對(duì)于個(gè)人自動(dòng)單元是很重要的。第二，你必須把電路和邏輯緊密的結(jié)合愛(ài)來(lái)。他認(rèn)為PLC適合應(yīng)用于場(chǎng)合有兩種，他說(shuō)：“第一，過(guò)程控制系統(tǒng)的型號(hào)不適合離散控制系統(tǒng)，剛開(kāi)始這些產(chǎn)品的價(jià)格非常的高。”一些廠家已經(jīng)將PLC的優(yōu)化程序應(yīng)用于過(guò)程控制中，他們十分確定PLC不會(huì)廣泛用于過(guò)程控制這樣的事情是不會(huì)發(fā)生的。過(guò)程控制中的PLCPLC還沒(méi)有廣泛的應(yīng)用于過(guò)程控制中。例如，用梯形圖邏輯寫(xiě)一個(gè)三角函數(shù)公式是非常困難的。但是最近高級(jí)編程語(yǔ)言已經(jīng)迅速發(fā)展。每年一度的最新PLC技術(shù)會(huì)上，我們調(diào)查PLC生產(chǎn)者關(guān)于以下這些問(wèn)題。現(xiàn)在，她被分解成單元模塊，并分給新的任務(wù)和應(yīng)用新的語(yǔ)言。PLCPLC(可編程邏輯控制器)現(xiàn)在面臨著甚至更加復(fù)雜的難題。一般來(lái)說(shuō)，所有部分都完全的驗(yàn)證是不可能的。在局部功能塊設(shè)計(jì)階段，單個(gè)功能將被設(shè)計(jì)出來(lái)，并予以驗(yàn)證。現(xiàn)代超大規(guī)模集成電路設(shè)計(jì)（Very Large Scale IntegrationVLSI）是及其復(fù)雜的，一個(gè)集成電路一般有幾百萬(wàn)個(gè)晶體管，而且產(chǎn)品開(kāi)發(fā)周期大都三年左右。尤其是，對(duì)如何簡(jiǎn)化一個(gè)繁冗而復(fù)雜的設(shè)計(jì)任務(wù)這一問(wèn)題，仍然沒(méi)有被科學(xué)的處理。這種有目的性的研究產(chǎn)生了一個(gè)副產(chǎn)品，就是通過(guò)推廣這中研究到系統(tǒng)工程設(shè)計(jì)領(lǐng)域，從而加固了我們對(duì)設(shè)計(jì)理論和技巧的基本理解。因此，軟件的使用周期花費(fèi)是總共花費(fèi)的一個(gè)固定不變的增長(zhǎng)部分。尤其是，可編程邏輯控制器（ＰＬＣ）程序設(shè)計(jì)從二十五年前的兩條主線，發(fā)展到現(xiàn)在的成千上萬(wàn)條。其結(jié)果是，一方面造成了大量而低效率的程序代碼，另一方面并沒(méi)有獲得高的硬件性能。系統(tǒng)復(fù)雜性：軟件工業(yè)被認(rèn)為是系統(tǒng)性能的破壞者和系統(tǒng)復(fù)雜性的產(chǎn)生者。同樣的，它也將改善軟件的質(zhì)量的可靠性，以及關(guān)系到系統(tǒng)的較高安全標(biāo)準(zhǔn)，尤其是這些對(duì)環(huán)境有危害影響的，比如：機(jī)場(chǎng)控制、公共鐵路運(yùn)輸。 ISO 157451, 1999]，但是，基本上這些標(biāo)準(zhǔn)都不能參與有效的程序和系統(tǒng)設(shè)計(jì)方面知識(shí)的革新。 IEC611313, 1993。在可編程邏輯控制器程序設(shè)計(jì)過(guò)程中，測(cè)試和調(diào)試可能會(huì)占用超過(guò)百分之五十的人力。例如，可編程邏輯控制器（ＰＬＣ）程序仍然依靠一種方便的有邏輯梯形圖的程序?qū)崿F(xiàn)模式。因此，一個(gè)大的挑戰(zhàn)是提供技術(shù)以限制自動(dòng)控制系統(tǒng)對(duì)變化需要和新機(jī)會(huì)的反應(yīng)，所以，設(shè)計(jì)和操作知識(shí)可以實(shí)時(shí)的被再次利用，在工業(yè)實(shí)踐中提供了一個(gè)重要的競(jìng)爭(zhēng)面。特別的，這個(gè)主題與隨后的部分的是有關(guān)的?？梢酝ㄟ^(guò)分析估計(jì)看狀態(tài)模型是否達(dá)到想要的目標(biāo)，第二，狀態(tài)模型的描述提供結(jié)構(gòu)描述，這個(gè)結(jié)構(gòu)描述可以說(shuō)明邏輯要求和如細(xì)節(jié)安全規(guī)則的限制。自動(dòng)控制系統(tǒng)是狀態(tài)模型用公式語(yǔ)言或等價(jià)的語(yǔ)言描述的。這項(xiàng)研究的真正目的是找到一個(gè)減少控制軟件發(fā)展過(guò)程的不穩(wěn)定性的方法，也就是說(shuō)，減少程序和調(diào)試時(shí)間以及他們的變化，以增強(qiáng)自動(dòng)控制系統(tǒng)的適應(yīng)性，并且通過(guò)調(diào)整軟件使得軟件可以再度使用。這個(gè)設(shè)計(jì)方法論包括以狀態(tài)轉(zhuǎn)換模型為基礎(chǔ)的精確的描述，這個(gè)轉(zhuǎn)臺(tái)轉(zhuǎn)換模型是自動(dòng)控制系統(tǒng)的抽象系統(tǒng)。PLC程序測(cè)試和排除錯(cuò)誤，再者，PLC控制系統(tǒng)不適合設(shè)計(jì)對(duì)適應(yīng)性和重構(gòu)有越來(lái)越多要求的生產(chǎn)系統(tǒng)。在許多的工業(yè)設(shè)計(jì)工程中，超過(guò)PLC不需要使用目前的以軟件設(shè)計(jì)為基礎(chǔ)軟件工程方法論，因?yàn)镻LC程序要求對(duì)軟件和硬件搜都要考慮到。一般來(lái)說(shuō)，和其他領(lǐng)域相比生產(chǎn)PLC的周期要短很多。特別的，PLC程序要解決的實(shí)際問(wèn)題是消除軟件錯(cuò)誤和減少老式梯形邏輯語(yǔ)言的花費(fèi)。Morley在演講中著重強(qiáng)調(diào)了這個(gè)方面。PLC的創(chuàng)造者Richard E. Morley十分肯定的認(rèn)為目前PLC市場(chǎng)是一個(gè)價(jià)值五十億的工業(yè)雖然PLC廣泛應(yīng)用于工業(yè)控制中，PLC控制系統(tǒng)的程序依然和語(yǔ)法有關(guān)。雖然計(jì)算機(jī)控制技術(shù)已經(jīng)產(chǎn)生，但是PLC控制因?yàn)樗母咝阅?、成本低、并且?duì)惡劣的環(huán)境有很強(qiáng)的適應(yīng)能力而在工業(yè)控制的廣泛應(yīng)用中保持優(yōu)勢(shì)。Fourth functional improvements, strong functional interface.外文資料譯文1968年，Richard E. Morley創(chuàng)造出了新一代工業(yè)控制裝置可編程邏輯控制器(PLC),現(xiàn)在，PLC已經(jīng)被廣泛應(yīng)用于工業(yè)領(lǐng)域，包括機(jī)械制造也、運(yùn)輸系統(tǒng)、化學(xué)過(guò)程設(shè)備、等許多其他領(lǐng)域。Second，programming visual, simple。s PLCs don39。s being automated doesn’t justify DCS[distributed control systems].With the starting price tags of those products being relatively high, a programmable controller makes sense for small, low loop count applications. The seconds where you have to integrate the loop closely with the sequential logic. Batch controller sere prime examples, where the sequence and maintaining the process variable are intertwined so closely that the benefits of having a programmable controller to do the sequential logic outweighs some of the disadvantages of not having a distributed control system.”Bill Barkovtz, president of Triconex, predicts that all future controllers that e out in the process control system business will embrace a lot more PLC technology and a lot more PLC functionality than they ever did before.”Communications and MAPCommunications are vital to an individual automation cell and to the automated factory as a whole. We39。3 PLC英文資料Design Theory DevelopmentToday, the primary focus of most design research is based on mechanical or electrical products. One of the byproducts of this proposed research is to enhance our fundamental understanding of design theory and methodology by extending it to the field of engineering systems design. A system design theory for largescale and plex system is not yet fully developed. Particularly, the question of how to simplify a plicated or plex design task has not been tackled in a scientific way. Furthermore, building a bridge between design theory and the latest epistemological outes of formal representations in puter sciences and operations research, such as discrete event system modeling, can advance future development in engineering design.Application in Logical Hardware DesignFrom a logical perspective, PLC software design is similar to the hardware design of integrated circuits. Modern VLSI designs are extremely plex with several million parts and a product development time of 3 years [Whitney, 1996]. The design process is normally separated into a ponent design and a system design stage. At ponent design stage, single functions are designed and verified. At system design stage, ponents are aggregated and the whole system behavior and functionality is tested through simulation. In general, a plete verification is impossible. Hence, a systematic approach as exemplified for the PLC program design may impact the logical hardware design.PLCPLC（programmable logical controller）face ever more plex challenge these days. Where once they quietly relays and gave an occasional report to a corporate mainframe, they are now grounded into cells, give new jobs and new languages, and are forced to pete against a growing array of control products. For this year’s annual PLC technology update, we queried PLC makers on these topics and more.Programming languagesHigher level PLC programming languages have been around for some time, but lately their popularity has been mushrooming. As Raymond Lavelle, vice president and general manager, Siemens Energy and Automation. Inc, Programmable Controls Division, points out :”As programmable controls are being used for more and more sophisticated operations, languages other than ladder logic bee more practical, efficient, and powerful. For example, it39。 ISO 157451, 1999] have been formed to fix and disseminate stateoftheart design methods, but they normally cannot participate in advancing the knowledge of efficient program and system design.A systematic approach will increase the level of design automation through reusing existing software ponents, and will provide methods to make largescale system design manageable. Likewise, it will improve software quality and reliability and will be relevant to systems high security standards, especially those having hazardous impact on the environment such as airport control, and public railroads.System ComplexityThe software industry is regarded as a performance destructor and plexity generator. Steadily shrinking hardware prices spoil