S7-300系列PLC与PC串口通信技术的研究与应用

在实际工业控制系统应用环境中,研究PLC与PC机之间的串口通信技术有助于实现PLC与Windows程序开发环境间的实时通信.基于对PLC与PC机之间的串口通信的研究,系统实现了Visual C 6.0与PLC的适时通信,从而实现工业控制系统中上下位机的通信,并将这种通信方法应用于实际工业环境,将由PLC采集的数据在上位机进行实时的显示以利于复杂系统的调试.     

用VC++6.0实现PLC与PC机之间的通信

介绍了利用PC机作为上位机，PLC（可编程控制器）作为下位机操作站时，用可视化编程语言VC＋＋6．0中的MSComm控件实现串口通信，运行结果表明此方法简单，稳定、实用性强。     

基于电话网实现上位机与三菱PLC的远程通信

研究了基于电话网实现了上位机与FX2N系列PLC远距离通信的方法。罗列了该系列PLC的通信模式，详细介绍了该系列PLC编程器的通信协议。具体阐述了在Visual C＋＋环境下，用MSComm控件实现串口通信的方法，并给出了串口初始化代码、Modem拨号及程序代码、数据帧生成及发送的程序代码等的实现程序。为进一步实现上位机对PLC的远距离监控提供了参考。     

VC++6.0编程中的串口通信技术在三菱PLC网桥中的应用

主要介绍在Visual C 6．0下应用通信控件开发串口通信程序的方法，使用PC上位机可视化界面配置挂接的模块，使模块输入输出与三菱PLC相对应，对于用三菱软件设计梯形图的用户可将系统完全视为三菱PLC系统。     

多线程串口通信在闭气塞检测系统中的应用

针对单线程进程机制通信开销大,系统工作效率低的问题,利用多线程技术和Windows API函数,开发设计了上位机的串行通信程序;根据PLC自由端口模式,设计了PLC的串口通信程序,从而实现了闭气塞自动检测装置中PLC和PC之间的通信.系统运行表明:基于自由口通信方式的上位机 PLC的自动检测控制系统,引入多线程后,检测效率明显提高,且性能稳定,可靠性高.     

C++ Builder下S7-200 PLC与计算机的通信

研究了在C＋＋ Builder开发环境下如何实现S7-200 PLC与上位计算机基于自由口模式通信的问题，通过详细分析自由口模式下通信协议的自定义及其实现方法，实现了过程控制系统中S7-200 PLC与上位机自由口模式通信，结合实例说明了通信过程中数据处理的方法，并给出了关键程序和运行结果。实践证明，在C＋＋ Builder下实现S7-200 PLC与计算机基于自由口模式的通信简单实用，具有很强的推广应用价值。     

RS-422串口通信在DSP中的设计与应用

串口通信在控制系统中广泛的应用,阐述了用TI公司TMS320LF2407与PC机如何进行串口通信,分别详细讲述了上位机与下位机的设计过程,使用C Builder 6.0作为开发工具开发上位机程序,利用DSP的SCI模块,成功的实现了上下位机通信,程序已在PC机与DSP实验板上调试通过.     

基于Proteus虚拟环境单片机与PC串口通信

Proteus虚拟环境提供的COMPIM组件,可用来设置单片机串口通信协议,使虚拟环境与实际PC通信成为可能。对于没有物理串口的PC机,可借助VSPD虚拟串口软件构建PC虚拟串口,仅用一台PC机就可实现单片机系统与PC串口通信。根据单片机串口通信的特点,提出了单片机与PC串口通信的结构模型,即应用层、数据链路层和物理层三层结构,探讨了串口通信结构模型与通信方式之间的关系。在Proteus环境中以虚拟串口为例,设计了硬件电路和通信程序、给出了串口通信程序流程图,在一台PC机上实现了单片机与PC串口通信。     

VC下的串口通信及其在平网印花系统中的应用

通过介绍VC下的串口通信在平网印花机的主从式监控系统中的应用,较系统地阐述了用VC^ 6.0开发上位机与PLC及多个单片机之间的串口通信程序的设计方法。     

基于C++Builder的PC机与单片机串口通信的实现

串口通信是人体重心实时监控软件的主要功能之一.介绍了串口通信协议的设计,研究了在C++ Builder环境下如何利用API函数开发上位机的通信程序,从而实现PC机与单片机的串口通信.经过试验测试和实际运行,通信程序能够准确、快速地完成通信任务.     

浅谈反映人体测量学来源的人体比例理论

人体测量学并不是现代社会的产物。有着很长发展历史的人体比例理论中就包含了现代人体测量学的基本内容,尽管其还不够系统完整,但至少说明了在艺术创作中诞生的人体比例理论对现代人体测量学的影响。并随着时间的推移而不断的完善发展,为现代人体测量学的系统提出奠定了坚实的基础。     

On the relation of the quality of the system with the configuration of the structure of its control device

By examples of the design in the input-output relations of control devices with various configurations, the dependence on the configuration of the value of the criteria characterizing the system quality is shown. The complexity of solving the problem in the state space is illustrated.     

长江水质预测的建模

分析了在长江水质的评价和预测建模过程中出现的一些问题,利用灰色模型的指数特性,建立预测长江水质的GM（1,1）的改进模型。根据数据的周期波动特性,采用灰色系统理论建立了残差序列周期修正GM（1,1）模型,用复合残差来修正预报数据,提高了数据预报的准确程度和模型的适用性。     

Study of the response of the area of the palm to impact: Relationship between the physical characteristic of the palm impact and the subject perception of the severity of the palm impact

Even though using the hand as a hammer causes injury, the practice continues, and may be increasing, in industry and in jobs that require intensive manual labor. This was an exploratory study aimed at measuring the relationships between the forces of strikes, the relative angles of strikes, and/or the number of strikes (up to 3) with the perception of severity of strikes when using the base of the palm of the hand. Eight subjects struck a metal force plate with the base of the palm of the hand at three levels of force, three levels of angle with respect to the surface of a force plate, and with three different numbers of times in a trial. Subjects were then asked to give a psychophysical rating after each trial. The subjective perception of the severity of each impact and force-time curves were recorded. From each force-time curve, peak force, maximum acceleration of force application, and the area of the force curve from initiation to peak were determined. Sixteen ANOVA models were analyzed.     

JSP实现基于中值排序基数法的BBS树状结构

用JSP实现基于中值排序基数法的BBS树状结构,给出数据结构的设计以及具体的算法实现。     

基于单机的虚拟网络实验平台的实现

为了能够解决学生网络实验的可操作性和实验室安全管理的稳定性之间的矛盾,引入VMware,从而在单机上实现虚拟网络实验平台,提高网络实验教学的课堂效果.     

基于单机的虚拟网络实验平台的实现

为了能够解决学生网络实验的可操作性和实验室安全管理的稳定性之间的矛盾,引入VMware,从而在单机上实现虚拟网络实验平台,提高网络实验教学的课堂效果。     

浅谈紫禁城的屋顶文化

紫禁城是我国古代建筑的精品,显示着古代匠师们在建筑上的卓越成就。其苦心经营的屋顶建构更是彰显了宫殿壮丽的威严和飞动的气势。随着我国城市化建设的加速发展,正确地认识中国传统建筑文化并设计具有中国文化的建筑迫在眉睫。本文将从紫荆城屋顶的造型和色彩两方面探析紫禁城的屋顶文化。     

Reconstruction of the corrective component of the transfer function of the interpolator in the process of calibration of the precision event timer

The peculiarities of the interpolation method based on digital signal processing are considered. It is shown that the transfer function of the interpolator may be represented by the composition of two functional components. A nonstatistical method of reconstruction of the form of the corrective component of the transfer function based on processing of the scatter diagram of the ordered pairs of the experimental and predicted data is investigated. It is shown that such pairs may be obtained in the process of periodic event flow timing with estimations of the time positions of the signal and the predetermined instants of the event occurrence being elements of the ordered pairs. The efficiency of the reconstruction method is illustrated by the experimental results.     

Convergence,the university of the future and the future of the university

 The paper questions the ability of current university systems to respond appropriately to the complex demands of an Information Economy. It argues that new relationships between creative subjects and technology require new thinking about the nature and purpose of universities per se. In particular, attention is drawn to the growing involvement of the private sector in higher education. It is argued that it may not be appropriate to think of the `university of the future' in terms of current public sector and quasi public sector institutions, but rather in terms of an emporium, based on an international trade in educational services, and with the `University' as we now understand it occupying the functions of licensing, quality assurance and cultural custodianship. Accepted: 25 June 2002