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中英文翻译三江学院 毕业设计(论文)外文资料翻译 院 系 电气系 专 业 电气及其自动化 学生姓名 秦昉 班级学号 B08071135 外文出处     附件:1.外文资料翻译译文(约3000汉字); 2.外文资料原文(与课题相关的1万印刷符号左右)。 指导教师评语: 指导教师签名: 年  月  日   1、PLC design criteria  A systematic approach to designing PLC software can overcom...

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三江学院 毕业 设计 领导形象设计圆作业设计ao工艺污水处理厂设计附属工程施工组织设计清扫机器人结构设计 ( 论文 政研论文下载论文大学下载论文大学下载关于长拳的论文浙大论文封面下载 )外文资料翻译 院 系 电气系 专 业 电气及其自动化 学生姓名 秦昉 班级学号 B08071135 外文出处     附件:1.外文资料翻译译文(约3000汉字); 2.外文资料原文(与课 快递公司问题件快递公司问题件货款处理关于圆的周长面积重点题型关于解方程组的题及答案关于南海问题 相关的1万印刷符号左右)。 指导教师评语: 指导教师签名: 年  月  日   1、PLC design criteria  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. 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. 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 PLCs 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. 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 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. Increased safety, for instance new policies on fire protection, and the flexibility of modern automation systems add complexity to the program design process. Consequently, the life-cycle cost of software is a permanently growing fraction of the total cost. 80-90% of these costs are going into software maintenance, debugging, adaptation and expansion to meet changing needs. 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. 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. 2、SIEMENS PLC  SIMATIC S7-300 series PLC applied to all walks of life and various occasions in the detection, monitoring and control of automation, its power to both the independent operation of, or connected to a network able to achieve complex control.  The photoelectric products with isolation, high electromagnetic compatibility; have high industrial applicability, allowing the ambient temperature of 60 ℃; has strong anti-jamming and anti-vibration and impact resistance, so in a harsh working environment has been widely Applications.  I also mean freedom of communication S7-300 type PLC' s a very unique feature, which allows S7-300-PLC can deal openly with any other communications equipment, communications controller, or PLC S7-300 type can be defined by the user's own Communications protocol (of the agreement ASCII), the baud rate to 1.5 M bit / s (adjustable). So that can greatly increase the scope of communications so that the control system configuration more flexible and convenient. Of any kind with a serial interface peripherals, such as: printers or bar code readers, Drives, a modem (Modem), the top PC-connected, and so can be used. Users can program to develop communication protocols, the exchange of data (for example: ASCII character code), RS232 interfaces with the equipment can also be used PC / PPI cable linking the free communication communications.  When the PC offline, under the control of the next crew, the whole system can operate normally.  PC that is by control centre, mainly by the PC and laser printer components, using SIMATIC WINCC software platform, the all-Chinese interface, friendly man-machine dialogue. Managers and operators can be observed through a PC, shown in the various kinds of information to understand the present and past the ice-storage operation of the automatic control system and all the parameters, and through the mouse to print equipment management and implementation tasks.  WINCC software in the field of automation can be used for all the operators’ control and monitoring tasks. Can be controlled in the process of the events clearly show, and shows the current status and order records, the recorded data can show all or select summary form, or may be required for editing, printing and output statements and trends .  WINCC able to control the critical situation in the early stages of the report, and the signal can be displayed on the screen, can also use sound to be felt. It supported by online help and operational guidelines to eliminate failure. WINCC a workstation can be devoted to the process control to the process so  that important information not is shielded. Software-assisted operation strategy ensures that the process was not illegal to visit and to provide for non-industrial environment in the wrong operation.  WINCC is MICRSOFT WINDOWS98 or WINDOWS NT4.0 operating system, running on a PC object-oriented class 32-bit application, OLE through the window and ODBC standard mechanism, as an ideal partner to enter the communications world WINDOWS, it can be easily WINCC To integrate a company-wide data processing system.  3、Communications Communications are vital to an individual automation cell and to the automated factory as a whole. We've heard a lot about MAP in the last few years, and a lot of companies have jumped on the band wagon. Many, however were disappointed when a fully-defined and completed MAP specification didn’t appear immediately. Says Larry Kumara:” Right now,  MAP is still a moving target for the manufacturers specification that is not final. Presently, for example, people are introducing products to meet the MAP 2.1standard.Yet 2.1-based products will be obsolete when the new standard for MAP, 3.0is introduced.” Because of this, many PLC vendors are holding off on full MAP implementations. Omron, for example, has an ongoing MAP-compatibility program, but Frank Newborn, vice president of Omron’s Industrial Division, reports that because of the lack of a firm definition, Omron's PLCs don't yet talk to MAP. Since it’s unlikely that an individual PLC would talk to broadband MAP anyway, makers are concentrating n proprietary networks. According to Sal Provanzano, users fear that if they do get on board and vendors withdraw from MAP, they all pulse width modulation control system be the ones left holding a communications structure that’s not supported. 1、PLC的设计标准 一个系统化的设计 PLC程序的方法可以克服传统程序生产控制系统的缺点,并且在一些工业应用总有很大的不同。自动控制系统是状态模型用公式语言或等价的语言描述的。公式描述对被控制的系统的行为提供一个精确的描述。可以通过分析估计看状态模型是否达到想要的目标。第二,为状态模型的描述提供结构描述,这个结构描述可以说明逻辑要求和如细节安全规则的限制。第三,好的控制系统设计是对自动控制代码生成有益的——一种能够产生可执行的控制软件的能力,不同的逻辑控制器可以减少程序扫描时间和执行那个时间。特别的,这个主题与随后的部分的是有关的。 在现代制造业中,系统是用过程和结果的革新来描述的,并且因此不得不改变系统性能以快速做出反应。因此,一个大的挑战是提供技术以限制自动控制系统对变化需要和新机会的反应,所以,设计和操作知识可以实时的被再次利用,在工业实践中提供了一个重要的竞争面。 研究表明,在自动化系统中,程序实现的方法已经与计算机资源应用的急速增长不能匹配。例如,可编程逻辑控制器(PLC)程序仍然依靠一种方便的有逻辑梯形图的程序实现模式。结果,程序上的延迟和资源成了生产工业过程的主要绊脚石。在可编程逻辑控制器程序设计过程中,测试和调试可能会占用超过百分之五十的人力。在发展和传播“STATE-OF-THE-ART”已经形成标准[IEC 60848, 1999; IEC-61131-3, 1993; IEC 61499, 1998; ISO 15745-1, 1999],但是,基本上这些标准都不能参与有效的程序和系统设计方面知识的革新。 系统的方法通过使用原有的软件模块,有助于增加设计自动化的水平,同时也将提供一种可管理的大规模系统设计的方法。同样的,它也将改善软件的质量的可靠性,以及关系到系统的较高安全标准,尤其是这些对环境有危害影响的,比如:机场控制、公共铁路运输。 软件工业被认为是系统性能的破坏者和系统复杂性的产生者。逐渐下降的硬件价格,破坏了对通过优化程序获得的软件性能的需要。其结果是,一方面造成了大量而低效率的程序代码,另一方面并没有获得高的硬件性能。其次,软件变得难以掌握其程度的复杂;在现代自动化系统中,软件设计和保持系统本质几乎变得不可能。尤其是,可编程逻辑控制器(PLC)程序设计从二十五年前的两条主线,发展到现在的成千上万条。现在安全性增加了,例如,关于防火的新 措施 《全国民用建筑工程设计技术措施》规划•建筑•景观全国民用建筑工程设计技术措施》规划•建筑•景观软件质量保证措施下载工地伤害及预防措施下载关于贯彻落实的具体措施 ,以及现代自动化系统的柔韧性增加了程序设计过程的复杂性。因此,软件的使用周期花费是总共花费的一个固定不变的增长部分。百分之八十到九十的花费用于软件维护、调试、优化(改进)、和扩展以满足不断变换的需求。 目前,大部分设计研究的主要焦点都集中在机械和电子产品上。这种有目的性的研究产生了一个副产品,就是通过推广这中研究到系统工程设计领域,从而加固了我们对设计理论和技巧的基本理解。针对大规模和复杂系统的系统设计理论并没有成熟。尤其是,对如何简化一个繁冗而复杂的设计任务这一问题,仍然没有被科学的处理。而且,正在设计理论和代表计算机科学及运筹学研究的认识论结果之间构建一条桥梁,这样的具体应该是逻辑硬件电路设计。 从逻辑学的角度来看,可编程逻辑控制器(PLC)的软件设计类似与集成电路的硬件设计。现代超大规模集成电路设计(Very Large Scale Integration--VLSI)是及其复杂的,一个集成电路一般有几百万个晶体管,而且产品开发周期大都三年左右。设计过程一般都分成局部功能块设计和系统设计两个阶段。在局部功能块设计阶段,单个功能将被设计出来,并予以验证。在系统设计阶段,所有功能块都将被整合起来,整个系统行为特性和功能将会通过仿真形式加以测试。一般来说,所有部分都完全的验证是不可能的。因此,统计学可以作为可编程逻辑控制器(PLC)设计的一个例子,并有可能影响逻辑硬件设计。
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