PROFIBUS-DP与HART协议转换研究及其网关设计

介绍了PROFIBUS和HART两种现场总线的特点,探讨了两种现场总线的协议的转换方法,并成功开发出了可将两种总线进行互连的网关模块,实现了两种现场总线的底层互连。     

现场总线在PLC应用中的解决方案

根据现场总线的特点，提出了现场总线在PLC应用中的两种方案：PLC＋现场总线或IPC＋软件PLC＋现场总线；实例表明在传统PLC控制中融入现场总线和计算机软件技术后，提升和改善了工业控制在现场通信网络、互操作性、分散功能以及开放式互连网络方面的应用水平；显然，这种灵活的集成方式是当前工控领域应用现场总线技术的有效途径。     

北京地铁五号线多通信协议设备集成解决方案

在北京地铁五号线项目设计和实施过程中,遇到的两个问题,一是多种总线协议标准共存,需要各种总线协议设备互连;二是供应商设备通信接口五花八门,需要统一连接到一种选定的工业通信网络及现场总线系统中。通过使用PROFIBUS总线桥可以方便的将多家第三方设备集成到PROFIBUS现场总线网络中,保证设备的实时监控和系统的可靠运行。     

现场总线控制网络与IP网络连接方法研究

自动控制系统无缝地集成到企业管理信息系统中是当今自动控制的一种发展趋势,该文提出了一种现场总线控制网络与IP网络的连接方法:OPC-SNMP方法,可实现基于现场总线的控制系统与IP网络的互连,从而满足远程监控与维护中对现场设备的访问要求。     

以太网与现场总线的互连方法

研究了现场总线和以太网的互连方法。该方法使现场总线和以太网结合起来,共同组成全分散、全开放的控制网络,并可以实现多种现场总线的系统集成。     

现场总线的网络结构

本文从网络技术出发，研究现场总线的网络拓扑结构、现场总线的数据通信工作方式及现场总线中网络扩展与网络互连问题。     

轨道交通中多通信协议设备集成解决方案

在轨道交通的项目设计和实施过程中,遇到的两个问题,一是多种总线协议标准共存,需要各种总线协议设备互连;二是供应商设备通信接口五花八门,需要统一连接到一种选定的工业通信网络及现场总线系统中。通过使用PROFIBUS总线桥可以方便的将多家第三方设备集成到PROFIBUS现场总线网络中,保证设备的实时监控和系统的可靠运行。本文将以北京地铁5号线为例进行介绍。     

测控系统总线综述

综述了测控系统中机箱底板总线、计算机与测控系统的互连总线和现场总线的历史、性能、应用和发展。     

混合有线/无线基金会现场总线的实现

与有线现场总线的混合使用是目前无线现场总线发展和应用的重要方向.无线基金会现场总线底层基于IEEE802.11.与有线基金会现场总线混合使用的方式包括:网络间的混合和现场H1网段内设备问的混合使用.混合网络利用不同的网络互连设备实现,混合H1网段则通过统一的通信机制和集成网桥和转发器的互连方式来实现.性能分析表明,实现方法可以满足不同混合使用的通信需求.     

名词点击

[现场总线标准] TS61158 可以支持各种工业领域的信息处理、监视和控制系统,用于过程控制传感器、执行器和本地控制器之间的低级通信,可以与工厂自动化的PLC实现互连。在这里,H1现场总线主要用于现场级,其速率为31.25Kbps,负责两线制向现场仪表供电,并能支持带总线供电设备的本     

Assessing Ideational and Evaluative Skills and Creative Styles and Attitudes

This article describes the rationale for the multiphase creative problem solving process, and reports the findings from an empirical investigation conducted to facilitate the problem solving of managers. The ideational skills of the managers were assessed before and after training in a complete process of creative problem solving, along with their ideational attitudes, creative problem solving style (i.e., generator, conceptualizer, optimizer, or implementor), and evaluative skill (i.e., ability to recognize original ideas). The most important findings indicated that the training had a significant impact on the evaluative accuracy of the managers. They were significantly more accurate in their judgments about original ideas after training, both in their identification of original ideas and their recognition of unoriginal ideas. After training, the managers also gave more solutions and more original solutions to problems. Finally, several variables (e.g., the “preference for active divergence” attitude, and the conceptualizer process style) seemed to moderate the impact of training. Training was therefore effective, with specific effects that can be predicted from pre-training individual differences in attitudes and process style.     

Rank and select revisited and extended

The deep connection between the Burrows–Wheeler transform (BWT) and the so-called rank and select data structures for symbol sequences is the basis of most successful approaches to compressed text indexing. Rank of a symbol at a given position equals the number of times the symbol appears in the corresponding prefix of the sequence. Select is the inverse, retrieving the positions of the symbol occurrences. It has been shown that improvements to rank/select algorithms, in combination with the BWT, turn into improved compressed text indexes.     

Semantics and verification of monitors and systems of monitors and processes

In this paper we present a sound and complete semantics for the monitor concept of C.A.R. Hoare. First a method for specification of monitors, introduced by O.-J. Dahl, is reviewed. This method is based on the relation between the historic sequence of monitor procedure calls and the historic sequence of monitor procedure exits. Based on such specifications and our new monitor semantics we present a method by which it is possible to prove that a concrete monitor is an implementation of an abstract one. In the last part of the paper an axiomatic semantics for systems of concurrent processes and monitors is introduced. The method supports verification by separation of concerns: Properties of the communication to and from each process are proven in isolation by a usual Hoare style axiomatic semantics, while abstract monitors are also specified in isolation by the method reviewed in the first part of the paper. These properties of the components of the system are then used in a new proof rule to conclude properties of the complete system. Stein Gjessing received a Ph.D. (actually a Dr. philos.) from the University of Oslo (Norway) in 1985. Presently he is an Associate Professor at the Institute of informatics, University of Oslo, Norway. Dr. Gjessings research interests are in the area of concurrent and distributed programming, operating systems, formal specification and verification and programming languages.     

Integrating and automating analysis and optimization

The development of an interface coupling program on personal computers for an analysis software system such as ANSYS, SAP, etc. and an optimization software system, MOST, is presented. By controlling and directing the communications the interface coupler integrates the two programs while retaining their versatility and interactive features. The integrated system is used to solve a numerical example of active noise control for a three-dimensional enclosure, in which an energy density level of control points is minimized by adding the sound source to cancel the unwanted noise. The interface coupling program automates with relatively low cost the iterative process for designing an engineering system, remaining flexible in acoustical modelling and efficient in equation solving. Also, the coupling interface is developed in a general-purpose way so that it can be expanded easily to integrate more analysis software packages of different kinds.