基于LabVIEW的虚拟对象PLC控制实现

论文编号:ZD623 论文字数:13256,页数:43，有外文翻译，

摘　要

在工业现场环境,我们经常通过接口通讯将PLC和计算机连接起来实现人机交互。从而形成远程控制.实现无人职守的功能。在这个方面,人机界面也做的很好,提供很多的协议,我们只要编制上层程序即可。但是人机界面存在着数据存储量少而且界面不是很友好的弱点。
在过程控制中，由于工业现场非常分散，I／0点数众多，各种仪表的工作环境非常恶劣，采用数据采集卡和LabVIEW开发平台来完成现场的数据采集和控制显然不可取。考虑到过程控制中的过程参数变化不是很快，而PLC恰恰可以克服数据采集卡在过程控制中的不足，并且具有较高的性能比，因而采取以PLC为下位机，以装有LabVIEW软件的工控机为上位机开发平台，通过RS232或RS485串口与PLC通讯，实现对工业现场的监控与现场数据的分析。
工控机这方面可以实现很好的补充.既能在复杂的工业环境上进行良好的控制,而且提供友好方便查询与处理的操作，实现方便。加上配合美国NI公司的LABVIEW实现具体的功能。稳定性和可靠性将大大提高。
LabVIEW是实验室虚拟仪器工程工作台LabVIEW Virtual Instruments Engineering Workbench)的简称，是美国国家仪器公司开发的虚拟仪器开发平台软件，他的功能强大灵活，可以广泛应用于自动测量系统、工业过程自动化、实验室仿真等各个领域。
LabVIEW使用图形化编程语言编程，简单直观，极大节省程序开发时间，同时LabVIEW可提供丰富的库函数和功能模块，可完成各种各样的复杂编程任务。
三菱PLC通过通讯模块FX2N实现计算机与PLC进行通讯，从而实现远程控制与管理。
本文采用LabVIEW作为开发平台，将虚拟仪器技术与PLC技术结合到一起，发挥各自的优势，完成PC机与PLC的串口通信，开发上位机控制系统，实现良好的人机界面与可靠的系统控制。
关键词：LabVIEW,虚拟对象,ＰLC
ABSTRACT

The scene in the industrial environment, we often through the interface PLC and computer communications will link up the realization of human-computer interaction. Thus remote control. No duty to achieve the functions in this context, human-computer interface has also done a very good offer a lot of agreement , We can be as long as the procedures for the preparation of the upper. But there is a human-computer interface less data storage interface is not very friendly but also weaknesses.
For example: in the process control, since the industry is very scattered at the scene, I / 0 points large variety of instruments working environment is very poor, using data acquisition card and LabVIEW development platform to complete the data acquisition and control is clearly undesirable. Taking into account the process control parameters in the process of change is not quickly and precisely PLC data acquisition card can be overcome in the process of inadequate control, and has higher performance than, thus the adoption of a PLC for the next crew to work with LabVIEW software Computer-controlled machine for the development platform, or through the RS232 Serial RS485 communication with the PLC, the realization of the industrial site monitoring and field data analysis.
IPC in this regard can be achieved very good supplementary. Both in complex industrial environment on good control, but also provide friendly and convenient for handling the operation. Realization of convenience. Coupled with the companies cooperating with the United States NI LABVIEW achieve specific functions. Stability and reliability will be greatly enhanced.
LabVIEW is the virtual instrument engineering laboratory table (LabVIEW Virtual Instruments Engineering Workbench), short for National Instruments is the development of the virtual instrument software development platform, its powerful flexibility, and can be widely used in automatic measurement systems, industrial process automation, Simulation Laboratory, and other fields.
LabVIEW use graphical programming language, simple and straightforward, great development time-saving procedures, LabVIEW can provide rich library function and function modules can be programmed to complete a variety of complex tasks.
Mitsubishi PLC realizes the computer and PLC through communication module FX2N carries on the communication, thus realizes the remote control and the management. this article uses the LabVIEW achievement to develop the platform, unifies the hypothesized instrument technology and the PLC technology together, displays the respective superiority, completes PC machine and the PLC serial port correspondence, the development superior machine control system, realizes the good man-machine contact surface and the reliable systems control. Mitsubishi PLC through the communications module FX2N PLC for the computer and communications so as to achieve remote control and management. By using virtual instrumentation (LabVIEW) to achieve PC serial communication with the PLC.

Keywords: LabVIEW,Virtual objects,PLC

目　录

第1章 绪 论 1
第2章 LabVIEW的简介 3
2.1 LabVIEW的特性 3
2.2 LabVIEW的运行机制 4
2.3 LabVIEW中的串口通信函数 9
第3章　FX2N-PLC的通信协议 11
3.1 位软元件的成批读 11
3.2 字软元件的成批读 12
3.3 位软元件的批写 13
3.4 字软元件的批写 14
3.5 位软元件测试 15
3.6 字软元件测试 16
3.7 远程运行/停止 16
3.8 类型代码 19
3.9 控制规程 20
3.10 全局功能 20
3.11 接通要求功能 21
3.12 环路回送测试 27
3.12.1命令 27
3.12.2规程 28
第4章  程序设计 29
4.1 环路回送测试程序图 29
4.2 数据读程序图 30
4.3 数据写程序图 31
4.4 程序的调试 32
第5章 总结与展望 35
5.1 总体情况 35
5.2 前景展望 35
参考文献 36
致　谢 38

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