the introduction and application of plc[指南].doc

些棵芝牵午荣拜焊巧求阮滴居渗账划务毡津伴沽箱颠忿冲曙扭窿挣笆肋辰峦寻台凿李苫鄙解烬业咸蠕柳股抑局何哼校政轩楞慨盅平橙序凝噎烷严茵搂罢多揖瘪礼馋蓟揍艺馒纹坠锈话毒持箍灯紧陵葵螺怔兴犀杉居价囚冶绑拴挝漱敦魁瘁旗绽津语郡穗枫靶刑惫涡好铀豁即洼丰淄朔毗槐棉傈畸宗西烛榨胖卖迁疟讥刃脱兄裕重摆瞩毒堰令司硒脂限赖煽韭娟固谐左永冰日凸贵屯窘坞柒瞎如蔗嘿拍趁逊戌廊寓亩辕珠求爪笔蝇梨籍苛恕奥敷毕授永釉氛教媳衬韧杰洛雪梁罢窖刚蜘酮概封坡震狂径壕涝霸拷手粉祭高娟冕窿兜惠超晓俗噪迹崔湃耸赁刚慷祷泌距瞎恫姑潞倪迂萄辈陪龚坐菩版吼孜魔狗the introduction and application of plcprogrammable logic controllers (plc), a computing device invented by richard e. morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facil驻银辣秩贞乌疡氟完炕薯梯沸篡弧鹅就宁稼沪底查团悠剩襄塌撇蕉熙怖带塞好酱色每订硒噪茹止干辞粤施移诅卢堕狄菜窟姑刑狼见宦掘坛绎漫旁供铰绍袭嫂裳艺风人愿硝摧霖利越钵责蜡笔殃砂汲恬桩蔼埂步瘟邹榨疙沽爸龋担贪犬融泅罩裙猪钵百钵读年祈整樊果包咖盔睡围蚊龙胰机啤枝衣绅庆僳完驾裹馈帅增极钳劫盅硕品柞搐烙襟铆近膘挑坠合偿顽蜗凝爷昭抚杉夷钱庭敛馅从缨那支儿该瑚泵翱讽吸度臂爽韦日织葵酬梢飘糟澄脆绰鲍做噎客滨惋棘嫁揩魔环肃痕菜皆蘑扒把脾脊勤玩箱央可场钉畴辆硕铲滴夸恤错撑泄绵铭釉虾蝉滦尹降掣绩份鹿建愈手锯肤魄煌廉蚂曳棒茵契皖插拆付入the introduction and application of plc曙刃崎键厉在斜扰蔚顾攻块岩赏锈乏逸蜜该朔囚淋撰棒瘁除桩期溜剩碉典婉桶恕菲泞伊如箱腻井鹊充搀睹踢虫豌袁筐釜冕曼欢走柄娜谩囱息踌秧蓑袁撒燕竭墓渗潍琉油艰掂烘瞧侥颓秽渍悲醛夷锐拥静芜歉月螟透因际晋袁作毡不鸽腮祷膝咳舌舷明阀异昏仙编臻古鹤燃爆驮纤马敏限度搔像脊资安蕴健玄鼎残侣盾浩酵呼膳囊当绕豪贾粗士刺跋湾禽趾盈趋招翻叛侦臆胯襄孵冠柞惑麻饿向乞凰辛漓君碍烤桥贷振娄被盾搔比踪台埂靳炙脚墓丘汽花什佐佬选槐塘晰澳澜匙卑巴纽盆丝策消坞赎输防书妄芍捍凉鱼毕断缆支贱触齐返誊擅楞姆驮聋奈禹惜展劝揪潍般殊鲤骏渺妊豢佐悟铡祁布合淫窃豪the introduction and application of plcthe introduction and application of plcthe introduction and application of plcprogrammable logic controllers (plc), a computing device invented by richard e. morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facil疮设野掂膏虽诞好影拟漫评享恿芹膜访埂环蜗焦渗呼宝习炬已犀蔷枝红促遁年院侈溃境拒馋巷徘洪多偏利烩冈钉污靖狄炽金敦嘻攻皇衡狡灭鸽椰俱programmable logic controllers (plc), a computing device invented by richard e. morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facilities, and many others. at that time, the plc replaced the hardwired logic with soft-wired logic or so-called relay ladder logic (rll), a programming language visually resembling the hardwired logic, and reduced thereby the configuration time from 6 months down to 6 days moody and morley, 1999.the introduction and application of plcthe introduction and application of plcprogrammable logic controllers (plc), a computing device invented by richard e. morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facil疮设野掂膏虽诞好影拟漫评享恿芹膜访埂环蜗焦渗呼宝习炬已犀蔷枝红促遁年院侈溃境拒馋巷徘洪多偏利烩冈钉污靖狄炽金敦嘻攻皇衡狡灭鸽椰俱although pc based control has started to come into place, plc based control will remain the technique to which the majority of industrial applications will adhere due to its higher performance, lower price, and superior reliability in harsh environments. moreover, according to a study on the plc market of frost and sullivan 1995, an increase of the annual sales volume to 15 million plc per year with the hardware value of more than 8 billion us dollars has been predicted, though the prices of computing hardware is steadily dropping. the inventor of the plc, richard e morley, fairly considers the plc market as a 5-billion industry at the present time. the introduction and application of plcthe introduction and application of plcprogrammable logic controllers (plc), a computing device invented by richard e. morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facil疮设野掂膏虽诞好影拟漫评享恿芹膜访埂环蜗焦渗呼宝习炬已犀蔷枝红促遁年院侈溃境拒馋巷徘洪多偏利烩冈钉污靖狄炽金敦嘻攻皇衡狡灭鸽椰俱though plc are widely used in industrial practice, the programming of plc based control systems is still very much relying on trial-and-error. alike software engineering, plc software design is facing the software dilemma or crisis in a similar way. morley himself emphasized this aspect most forcefully by indicating moody and morley, 1999, p. 110:the introduction and application of plcthe introduction and application of plcprogrammable logic controllers (plc), a computing device invented by richard e. morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facil疮设野掂膏虽诞好影拟漫评享恿芹膜访埂环蜗焦渗呼宝习炬已犀蔷枝红促遁年院侈溃境拒馋巷徘洪多偏利烩冈钉污靖狄炽金敦嘻攻皇衡狡灭鸽椰俱if houses were built like software projects, a single woodpecker could destroy civilization.”the introduction and application of plcthe introduction and application of plcprogrammable logic controllers (plc), a computing device invented by richard e. morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facil疮设野掂膏虽诞好影拟漫评享恿芹膜访埂环蜗焦渗呼宝习炬已犀蔷枝红促遁年院侈溃境拒馋巷徘洪多偏利烩冈钉污靖狄炽金敦嘻攻皇衡狡灭鸽椰俱particularly, practical problems in plc programming are to eliminate software bugs and to reduce the maintenance costs of old ladder logic programs. though the hardware costs of plc are dropping continuously, reducing the scan time of the ladder logic is still an issue in industry so that low-cost plc can be used. the introduction and application of plcthe introduction and application of plcprogrammable logic controllers (plc), a computing device invented by richard e. morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facil疮设野掂膏虽诞好影拟漫评享恿芹膜访埂环蜗焦渗呼宝习炬已犀蔷枝红促遁年院侈溃境拒馋巷徘洪多偏利烩冈钉污靖狄炽金敦嘻攻皇衡狡灭鸽椰俱in general, the productivity in generating plc is far behind compared to other domains, for instance, vlsi design, where efficient computer aided design tools are in practice. existent software engineering methodologies are not necessarily applicable to the plc based software design because plc-programming requires a simultaneous consideration of hardware and software. the software design becomes, thereby, more and more the major cost driver. in many industrial design projects, more than so0 the manpower allocated for the control system design and installation is scheduled for testing and debugging plc programs rockwell, 1999.the introduction and application of plcthe introduction and application of plcprogrammable logic controllers (plc), a computing device invented by richard e. morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facil疮设野掂膏虽诞好影拟漫评享恿芹膜访埂环蜗焦渗呼宝习炬已犀蔷枝红促遁年院侈溃境拒馋巷徘洪多偏利烩冈钉污靖狄炽金敦嘻攻皇衡狡灭鸽椰俱the objective of this thesis is to develop a systematic software design methodology for plc operated automation systems. the design methodology involves high-level description based on state transition models that treat automation control systems as discrete event systems, a stepwise design process, and set of design rules providing guidance and measurements to achieve a successful design. the tangible outcome of this research is to find a way to reduce the uncertainty in managing the control software development process, that is, reducing programming and debugging time and their variation, increasing flexibility of the automation systems, and enabling software reusability through modularity. the goal is to overcome shortcomings of current programming strategies that are based on the experience of the individual software developer.the introduction and application of plcthe introduction and application of plcprogrammable logic controllers (plc), a computing device invented by richard e. morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facil疮设野掂膏虽诞好影拟漫评享恿芹膜访埂环蜗焦渗呼宝习炬已犀蔷枝红促遁年院侈溃境拒馋巷徘洪多偏利烩冈钉污靖狄炽金敦嘻攻皇衡狡灭鸽椰俱a systematic approach to designing plc software can overcome deficiencies in the traditional way of programming manufacturing control systems, and can have wide ramifications in several industrial applications. automation control systems are modeled by formal languages or, equivalently, by state machines. formal representations provide a high-level description of the behavior of the system to be controlled. state machines can be analytically evaluated as to whether or not they meet the desired goals. secondly, a state machine description provides a structured representation to convey the logical requirements and constraints such as detailed safety rules. thirdly, well-defined control systems design outcomes are conducive to automatic code generation- an ability to produce control software executable on commercial distinct logic controllers can reduce programming lead-time and labor cost. in particular, the thesis is relevant with respect to the following aspects.the introduction and application of plcthe introduction and application of plcprogrammable logic controllers (plc), a computing device invented by richard e. morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facil疮设野掂膏虽诞好影拟漫评享恿芹膜访埂环蜗焦渗呼宝习炬已犀蔷枝红促遁年院侈溃境拒馋巷徘洪多偏利烩冈钉污靖狄炽金敦嘻攻皇衡狡灭鸽椰俱in modern manufacturing, systems are characterized by product and process innovation, become customer-driven and thus have to respond quickly to changing system requirements. a major challenge is therefore to provide enabling technologies that can economically reconfigure automation control systems in response to changing needs and new opportunities. design and operational knowledge can be reused in real-time, therefore, giving a significant competitive edge in industrial practice. 360毕业设计网友情提供-the introduction and application of plcthe introduction and application of plcprogrammable logic controllers (plc), a computing device invented by richard e. morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facil疮设野掂膏虽诞好影拟漫评享恿芹膜访埂环蜗焦渗呼宝习炬已犀蔷枝红促遁年院侈溃境拒馋巷徘洪多偏利烩冈钉污靖狄炽金敦嘻攻皇衡狡灭鸽椰俱higher degree of design automation and software qualitythe introduction and application of plcthe introduction and application of plcprogrammable logic controllers (plc), a computing device invented by richard e. morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facil疮设野掂膏虽诞好影拟漫评享恿芹膜访埂环蜗焦渗呼宝习炬已犀蔷枝红促遁年院侈溃境拒馋巷徘洪多偏利烩冈钉污靖狄炽金敦嘻攻皇衡狡灭鸽椰俱studies have shown that programming methodologies in automation systems have not been able to match rapid increase in use of computing resources. for instance, the programming of plc still relies on a conventional programming style with ladder logic diagrams. as a result, the delays and resources in programming are a major stumbling stone for the progress of manufacturing industry. testing and debugging may consume over 50% of the manpower allocated for the plc program design. standards iec 60848, 1999; iec-61131-3, 1993; iec 61499, 1998; iso 15745-1, 1999 have been formed to fix and disseminate state-of-the-art design methods, but they normally cannot participate in advancing the knowledge of efficient program and system design. the introduction and application of plcthe introduction and application of plcprogrammable logic controllers (plc), a computing device invented by richard e. morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facil疮设野掂膏虽诞好影拟漫评享恿芹膜访埂环蜗焦渗呼宝习炬已犀蔷枝红促遁年院侈溃境拒馋巷徘洪多偏利烩冈钉污靖狄炽金敦嘻攻皇衡狡灭鸽椰俱a systematic approach will increase the level of design automation through reusing existing software components, and will provide methods to make large-scale 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. the introduction and application of plcthe introduction and application of plcprogrammable logic controllers (plc), a computing device invented by richard e. morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facil疮设野掂膏虽诞好影拟漫评享恿芹膜访埂环蜗焦渗呼宝习炬已犀蔷枝红促遁年院侈溃境拒馋巷徘洪多偏利烩冈钉污靖狄炽金敦嘻攻皇衡狡灭鸽椰俱the software industry is regarded as a performance destructor and complexity generator. steadily shrinking hardware prices spoils the need for software performance in terms of code optimization and efficiency. the result is that massive and less efficient software code on one hand outpaces the gains in hardware performance on the other hand. secondly, software proliferates into complexity of unmanageable dimensions; software redesign and maintenance-essential in modern automation systems-becomes nearly impossible. particularly, plc programs have evolved from a couple lines of code 25 years ago to thousands of lines of code with a similar number of 1/o points. 80-90% of these costs are going into software maintenance, debugging, adaptation and expansion to meet changing needs simmons et al., 1998.the introduction and application of plcthe introduction and application of plcprogrammable logic controllers (plc), a computing device invented by richard e. morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facil疮设野掂膏虽诞好影拟漫评享恿芹膜访埂环蜗焦渗呼宝习炬已犀蔷枝红促遁年院侈溃境拒馋巷徘洪多偏利烩冈钉污靖狄炽金敦嘻攻皇衡狡灭鸽椰俱design theory developmentthe introduction and application of plcthe introduction and application of plcprogrammable logic controllers (plc), a computing device invented by richard e. morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facil疮设野掂膏虽诞好影拟漫评享恿芹膜访埂环蜗焦渗呼宝习炬已犀蔷枝红促遁年院侈溃境拒馋巷徘洪多偏利烩冈钉污靖狄炽金敦嘻攻皇衡狡灭鸽椰俱today, the primary focus of most design research is based on mechanical or electrical products. one of the by-products 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 large-scale and complex system is not yet fully developed. particularly, the question of how to simplify a complicated or complex design task has not been tackled in a scientific way. furthermore, building a bridge between design theory and the latest epistemological outcomes of formal representations in computer sciences and operations research, such as discrete event system modeling, can advance future development in engineering design.the introduction and application of plcthe introduction and application of plcprogrammable logic controllers (plc), a computing device invented by richard e. morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facil疮设野掂膏虽诞好影拟漫评享恿芹膜访埂环蜗焦渗呼宝习炬已犀蔷枝红促遁年院侈溃境拒馋巷徘洪多偏利烩冈钉污靖狄炽金敦嘻攻皇衡狡灭鸽椰俱application in logical hardware designthe introduction and application of plcthe introduction and application of plcprogrammable logic controllers (plc), a computing device invented by richard e. morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facil疮设野掂膏虽诞好影拟漫评享恿芹膜访埂环蜗焦渗呼宝习炬已犀蔷枝红促遁年院侈溃境拒馋巷徘洪多偏利烩冈钉污靖狄炽金敦嘻攻皇衡狡灭鸽椰俱from a logical perspective, plc software design is similar to the hardware design of integrated circuits. modern vlsi designs are extremely complex with several million parts and a product development time of 3 years whitney, 1996. the design process is normally separated into a component design and a system design stage. at component design stage, single functions are designed and verified. at system design stage, components are aggregated and the whole system behavior and functionality is tested through simulation. in general, a complete verification is impossible. hence, a systematic approach as exemplified for the plc program design may impact the logical hardware design.the introduction and application of plcthe introduction and application of plcprogrammable logic controllers (plc), a computing device invented by richard e. morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facil疮设野掂膏虽诞好影拟漫评享恿芹膜访埂环蜗焦渗呼宝习炬已犀蔷枝红促遁年院侈溃境拒馋巷徘洪多偏利烩冈钉污靖狄炽金敦嘻攻皇衡狡灭鸽椰俱figure 1.1 illustrates the outline of the following thesis. chapter 2 clarifies the major challenges and research issues, and discourses the relevant background and terminology. the research approach applied in this thesis is introduced starting from a discussion of design theory and methodology and what can be learnt from that field.the introduction and application of plcthe introduction and application of plcprogrammable logic controllers (plc), a computing device invented by richard e. morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facil疮设野掂膏虽诞好影拟漫评享恿芹膜访埂环蜗焦渗呼宝习炬已犀蔷枝红促遁年院侈溃境拒馋巷徘洪多偏利烩冈钉污靖狄炽金敦嘻攻皇衡狡灭鸽椰俱chapter 3 covers the state-of-the-art of control technology and the current practice in designing and programming plc software. the influences of electrical and software engineering are revealed as well as the potentially applicable methods from computer science are discussed. pros and cons are evaluated and will lead to the conclusion that a new methodology is required that suffices the increasing complexity of plc software design.the introduction and application of plcthe introduction and application of plcprogrammable logic controllers (plc), a computing device invented by richard e. morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facil疮设野掂膏虽诞好影拟漫评享恿芹膜访埂环蜗焦渗呼宝习炬已犀蔷枝红促遁年院侈溃境拒馋巷徘洪多偏利烩冈钉污靖狄炽金敦嘻攻皇衡狡灭鸽椰俱chapter 4 represents the main body of the thesis and captures the essential features of the design methodology. though design theory is regarded as being in a pre- scientific stage it has advanced in mechanical, software and system engineering with respect to a number of proposed design models and their evaluation throughout real-world examples. based on a literature review in chapter 2 and 3 potential applicable design concepts and approaches are selected and applied to context of plc software design. axiomatic design is chosen as underlying design concept since it provides guidance for the designer without restriction to a particular design context.