现场控制

FOUNDATION fieldbus is a bi-directional communications protocol used for communications among field instrumentation and control systems.

基金会现场总线是一种双向通信协议，用与现场仪表和控制系统之间的通信。

A LonWorks fieldbus based traffic signal control system is designed and developed in this paper.

现场应用结果表明：LonWorks现场总线技术的应用可大大提高交通信号控制系统的稳定性和可靠性。

Comparing to normal communication bus, the data communication of CAN bus has excellent character...

是目前流行的现场总线控制系统之一，也是到目前为止唯一有国际标准的现场总线。

On the base of traditional DCS,the fieldbus was used to this system.

该系统在传统的DCS基础上，尝试引进了现场总线技术，提出了基于现场总线的DCS控制系统。

According to actual condition, a model of wall thickness of rotary kiln is established. The constant coefficients in the model, including thermal conductivity, heat transfer coefficient, Fourier coefficient and contact resistance, are closely calculated. A formula of contact resistance is draw from a great deal of data of surface and inner temperature of rotary kiln. The wall thickness of rotary kiln is simulated by MATLAB. The simulation result is transmitted from MATLAB to DELPHI through a group of interface functions compiled by VC++. The basic graphs-circle and line are analyzed by the means of the technique of Visualization in Scientific Computing and the Bresenham arithmetic, and are realized the visualization of the wall thickness. The contents of communication between master computer and slaver computer are designed and the error control technique, the idea of multi-thread and the embedded assembly language are applied to realize the temperature data transmission and graph transmission, which largely improved the speed of transmission and the reliability and stability of system.

建立了符合现场实际的回转窑壁厚数学模型；结合现场采用红外测温仪测量所得的温度数据和回转窑的实际结构数据，确定出适合该模型的定常系数(包括导热系数、换热系数、傅立叶系数、接触热阻等)，并得出与回转窑工况的相近的接触热阻公式ln=T~(0.5154)-36.7868；利用MATLAB软件仿真出回转窑壁厚，并将运算结果通过在VC++的编译环境下编译出MATLAB和DELPHI的接口函数传输到该监测系统中，实现了温度数据的转换和交换；运用科学计算可视化技术和Bresenham扫描转换算法对基本图形——圆和直线进行分析，从而实现了仿真后的壁厚数据可视化；在研究异步串行通信方式的基础上，设计了该系统上下位机功能和通信内容，并运用差错控制技术、多线程思想以及嵌入式汇编语言实现了温度数据和图形数据在上下位机之间的远程传输，提高了数据传输的速率和系统的可靠性、稳定性。

Sensor and controller inconstantly demand on combination kind and working parameters of data acquisition module in many moni2 toring and control systems design.

本文采用MCS51 单片机为控制器，给出了控制采集端口的组合方式及工作参数可以根据现场传感器件的要求来定制现场数据采集模块的总体方案设计。

The following functions can be realized: Measuerment:the effective values of three phase current and voltage, power frequency, active power, reactive power, power factor etc. Motor control: direct starting, converse starting, star and triangle starting, self-starting. Protection:thermal overload protection, current leakage protection, open-phase protection, three-phase unbalance protection, over voltage protection, loss voltage protection, low load protection and fault warning and fault dates memory. Communication: communication of the computer in control room and the microcomputer monitor in the spots is realized by the interface of RS-485. The motor is not only controlled in the spots but also in control room. The dates, information and some functions are shared by the spots and control room too.

该电动机监控器以80C196KC单片机为核心，通过采样三相电流﹑电压信号来实现以下功能：三相电流﹑电压有效值，电网频率，有功功率，无功功率及功率因数等的测量；对电动机实现直接、正反转、星三角及自起动控制；对电动机实现热过载、漏电、断相、三相不平衡、过压、欠压及轻载保护，对故障进行报警及数据记忆；通过RS-485串行接口与中央控制室计算机实现通信功能，对电动机既可本地，也可远程控制；实现控制现场与控制室之间数据、信息、功能共享。

The simulation of field data indicates that this method avoids the effects of parameter variations by letting AFC and AGC to adaptively track the parameters variations for reducing disturbances. It ensures a good performance in decoupling,and improves the precision of flatness and gauge control.

现场实际数据的仿真结果表明，该方法的应用消除了参数变化产生的影响，使板形板厚控制系统具有良好的自适应跟随参数变化和抗干扰性能，解耦控制效果良好，提高了板形板厚的控制精度。

This paper is focused on the design scheme for stage machinery control system which is FCS.

本文着重阐述了舞台机械控制系统的设计方案，确定控制系统采用现场总线控制系统FCS。

In this paper,based on field investigation of Kiruna mine,Sweden,and strata control rules,block Y28 on level 632 in the mine is designed and modeled by means of the computer aided design system with strata control rules,and some of conclusions on strata control and computer aided design in stope are drawn.

根据瑞典北部Kiruna矿的现场调查，采用考虑岩层控制规律的CAD系统，对该矿632水平Y28采区进行了设计模拟，得出了如下结论：1.CAD设计中必须考虑岩层控制规律，与大规模开采有关的问题可通过考虑岩层控制规律得到改善。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了