基于工业自动控制的单片机与PLC串行通信

我国现代工业的突飞猛进,使工业自动控制水平不断提高,与此同时,在工业自动控制领域中,对单片机与PLC的研究也愈发深入,将单片机与PLC应用于工业自动控制领域中,能够有效解决工业设备的远程通信问题,不过,对于如何利用单片机与PLC来实现串行通信,以此充分发挥其技术优势,也已成为自动控制系统在设计过程中迫切需要解决的难题。为此,本文对基于工业自动控制的单片机与PLC串行通信进行深入的研究与探讨。     

项目教学法在工程机械PLC与单片机课程中的运用

工程机械PLC与单片机课程以具体的工程机械PLC与单片机控制系统项目为主线,按照基于工作过程设置项目,任务驱动方式将工程机械PLC与单片机控制系统的相关内容融入其中,让学生在教师指导的基础上实现做中学,学中做,学做合一,培养学生的自主学习和实践能力,有效提高教学质量。     

PLC、单片机的外设模拟系统

PLC、单片机技术在工业领域应用广泛,如把工矿企业的控制对象搬到学校,对训练学生PLC、单片机综合设计能力将起到很好的作用。由于控制对象形象直观、真实,能激发学生学习PLC、单片机等课程的兴趣和积极性。许多院校都有PLC、单片机实验箱和实验设备。但使用起来有一定的局限性,大多数只做一些固定的实验内容。我院研制了“PLC、单片机综合实验外设模拟系统”。它模拟了工业控制对象,可以随意组合构成多种控制要求,以满足不同层面的需要,可用于综合实验、课程设计、毕业设计、科技制作培训等环节。作为控制对象,既可用PLC控制,也可…     

基于MODBUS协议的单片机与S7-200PLC串行通信的实现

采用MODBUS通信协议,以ATMEGA16单片机为主机,S7-200PLC为从机,设计了两者之间的RS232/RS485方式的串行通信硬件电路,实现了基于MODBUS协议的单片机与PLC之间的串行通信.     

单片机与PLC的串行通信及其应用

本提出了可编程序控制器(PLC)与单片机之间实现串行通信的新概念,以松下电工FPI系列PLC和MCS-51单片机的通信为例．重点阐述了通信接口的实现方法,介绍一种实用的操作、显示单元。     

PLC实验箱模拟系统设计与实现

介绍一种PLC实验箱模拟系统,用于配合PLC实验平台完成“轿厢式电梯控制”“流水线产品计数”实验,能根据PLC控制程序的运行状态直观、形象地模拟演示实验现象;提出用单片机作控制器,用多只条式发光二极管灯组显示电梯和传送带的移动现象的方法;给出单片机I／O口扩展和单片机与PLC的通信电路原理图,并详细介绍模拟系统的软件设计方法。     

单片机与PLC的串行通信及其应用

本文提出了可编程序控制器（PLC）与单片机之间实现串行通信的新概念,以松下电工FPI系列PLC和MCS-51单片机的通信为例,重点阐述了通信接口的实现方法,介绍一种实用的操作、显示单元。     

基于PLC和单片机的多模式综合实验系统设计

为了与工业发展趋势一致,使学生具有综合的相关控制知识与实践能力,将不同的控制系统进行组合,设计了一种基于PLC和单片机的多模式综合实验系统。该实验系统由PC机、PLC、单片机和变频器组成,集PLC技术、单片机技术、变频调速技术、组态软件技术于一体,融合了多种通信接口和DDE的数据交互模式。实验表明,该系统大大拓展了学生的视野,为开设综合性创新实验提供了良好的平台。     

基于气动机械手综合实验的开发与应用

以三自由度气动机械手为实验对象,开发出5个机电专业综合实验.这些实验涉及了气动系统的组成、单片机控制技术、PLC控制技术、计算机与单片机组成的集散控制系统、以及多机械手协同作业等内容,应用效果理想.     

PLC编程方式在8031单片机设计中的应用

本文介绍了在8031单片机设计中采用PLC编程技术的操作原理,并以实例说明借鉴PLC技术可使8031单片机系统的开发更简单、经济、可靠。     

开放式试题生成管理系统的设计与开发

本文论述了OLE技术的工作原理,讨论了开放式试题生成 管理系统的设计与实现,并介绍了系统的关键技术。     

基于PLC的泵流量控制系统研究

为了提高泵的流量控制系统的精度,其运用西门子s7-200 PLC对泵的流量进行控制,阐述了泵的流量控制原理;PID控制原理以及PID控制在s7-200 PLC中的应用。结合PLC系统接线原理图;确定PLC的I/O分配表;进而确定硬件电路连接,利用s7-200 PLC中自带的PID向导生成PID控制程序,运用PID控制面板实现在线监控,同时采用语句表和梯形图对泵的流量进行控制。结果表明：两种方法都能实现对泵的流量控制,均提高了泵的流量控制的精度,满足工业生产的要求,同时实现了自动化控制,节约了时间和成本,提高了效率。     

基于S7—1200的UPS电源电气测试性能分析研究

针对UPS电源出厂前电气测试过程需人为操作,设计了UPS电源电气测试系统,采用S7—1200PLC作为系统的核心,以功率表作为测量元件,测试数据通过RS485通信方式送至S7—1200中,结合层次分析法、关联度分析法对其进行综合分析,利用组态王组态软件编制显示画面。在STEP7中对程序调试以及监控,与组态王组态软件连接,结果表明,该系统能够自动检测UPS电源电气测试数据并进行综合分析。     

PLC在草坪喷灌控制系统中的应用

PLC可编程序控制器具有编程简单、易学、维护方便、可靠性高、体积小等优点，越来越多地应用于自动控制系统中。笔者尝试设计利用PLC实现体育场草坪喷灌自动控制系统，简单介绍了PLC在工业自动化控制中的应用。     

提高PLC教学有效性的策略探析

随着我国经济发展,工业自动化技术提高,PLC技术被广泛应用于工业领域,而PLC课程恰是中职学校电子应用、机电技术应用等专业重要的基础课。随着PLC应用越来越广泛,采取一定教学策略,不仅能提高中职学校的PLC教学的有效性,还能培养学生学习能力及综合素质,为社会输出大量优秀人才,本文就PLC教学有效性的策略提高进行了分析探讨。     

LIFELONG EDUCATION AND THE UNIVERSITIES OF THE UNITED KINGDOM

The higher education system of the United Kingdom, of which the universities are only part, is changing rapidly. Although broad social conditions explain why universities should be centres of lifelong learning and specific institutional needs are in fact pushing them in this direction, changing demography is only one explanation among many. The kinds of programmes and related policies concerning students, teaching and curricula which are seen as relevant to continuing or lifelong education are widening and diversifying as the political and funding environment of higher education also changes. Research on continuing education and that generated by it are also being perceived differently. The new decade of the 1990's seems likely to witness significant changes in what is identified as continuing education as present trends in favour of integration or mainstreaming accelerate and new arrangements are made for more accessible and flexible forms of study both for degrees and for short courses. This process will be a part of a wider and more fundamental change as higher education moves somewhat towards a mass from an élite model and as the concept of a university and of a university education changes in step behind these changes in practice. The possibility exists that more fundamental changes in the initial undergraduate curriculum will also make universities more effective centres in terms of preparing their young students for lifelong learning.     

苏轼、苏辙和"苏门四学士"辞赋研究综述

北宋是辞赋发展的重要阶段,而苏轼、苏辙和“苏门四学士“的辞赋创作又是北宋中后期辞赋创作的重要组成部分。但由于种种原因,历代对苏轼、苏辙和“四学士“的研究多集中于他们的诗、文、词、文艺理论乃至书画等方面,对他们辞赋创作的基本情况和取得的成就则缺乏系统的梳理和恰当的评价。本文拟就苏轼、苏辙和“四学士“辞赋数量的统计、作品的研究、成就的评定等几个方面对历来的研究状况略作回顾。以推进此六人辞赋研究向深度和广度发展。这对全面评价此六人的文学成就,探讨苏门的创作特征,更加深入地研究辞赋这一特殊文体,都应是不无裨益的。     

THE CHURCH AND THE CITY

Abstract

This article mingles stories and concepts of young Jewish Israeli children about God, with reflections on the roles of faith, memory, imagination, and cognitive development in children's Religious Education. The stories are meant to illustrate, among other things, the purity and innocence of young children's faith, which is largely untroubled by fact. Then, using Vygotsky's notions of children's spontaneous concepts and the development of more mature and accurate conceptions in the “zone of proximal development,” a central dilemma in Religious Education will be explored. How can religious educators help young people acquire accurate historical information, textual skills, and theological methods of inquiry, while at the same time nurturing the precious flame of faith? Can we do better at combining systematic learning with pure faith? Toward this purpose, three complementary goals of Religious Education will be suggested: cognitive, practical/moral, and spiritual.     

TELEVISION AND THE EDUCATION OF THE YOUNG

This paper, from the 1979 Conference, ‘Television In Society’ begins by defining the educational process as one of persisting, despite initial failures, to acquire understanding or mastery, and underlining the uniqueness of each individual learner. The author reports on the results of a one‐year study of the viewing habits of pre‐school children. Little ‘rising fives’ are such heavy viewers that they must feel a sense of loss when school attendance deprives them of ‘their’ television, perhaps the most valuable ‘child‐minder’ of all. Television delights these veteran under‐five viewers and provides an aid that parents and teachers can welcome; it also seems to stimulate little or no ‘participation’ and to inhibit language skills. Older children are also voracious viewers, but the author's experience suggests that television does not of itself inhibit reading and that to blame violent behaviour on viewing of violence is humbug. In conclusion it is suggested that educators are as yet failing to recognize the paramount importance of television in children's lives: there is an urgent need for education to acknowledge this in its curricula and for children (and adults) to find out more about how television is created. The Educational Television Association could play an important role here.     

OPERATIONAL DEVELOPMENTS IN QUALITY ASSESSMENT AND INSTITUTIONAL ACCREDITATION IN HIGHER EDUCATION IN THE SLOVAK REPUBLIC

The Accreditation Commission of Slovakia was created in 1990, six months after passage of the Higher Education Law. The accreditation procedure stresses decentralization and participation at all levels; however, it leads to major decisions concerning the disapproval or approval of given faculties and appointments to professorships. Institutions as a whole are still not subjected to accreditation procedures. The Accreditation Commission has gained wide acceptance. Its judgments can be expected to influence the financing of given faculties and programmes in the future.