MODBUS 协议是应用于电子控制器上的一种通用应用层协议，通过此协议，控制器相互之间、控制器经由以太网或串行通信网络和其它设备之间可以通信。工业控制器连网也为网络管理提供了方便。MODBUS就是工业控制器的网络协议的一种，它已经成为主流工业标准之一。相互通信的连网为不同厂商生产的控制设备可以连成工业网络，进行集中监控提供了方便。
LabVIEW是一种程序开发环境，由美国国家仪器（NI）公司研制开发，类似于C和BASIC开发环境，但是LabVIEW与其他计算机语言的显著区别是：其他计算机语言都是采用基于文本的语言产生代码，而LabVIEW使用的是图形化编辑语言G编写程序，产生的程序是框图的形式。 LabVIEW软件是NI设计平台的核心，也是开发测量或控制系统的理想选择。 LabVIEW开发环境集成了工程师和科学家快速构建各种应用所需的所有工具，旨在帮助工程师和科学家解决问题、提高生产力和不断创新。
本次设计采用89E516RD单片机、ADM2582隔离型RS-485收发器，利用SIPEX SP3223EEY芯片 RS232转换器构成的系统，89E516RD单片机作为下位机，应用LABVIEW软件编制的上位机监控程序，应用单片机内部集成A/D转换器完成对实时电位器电阻模拟量的采集和处理，而LABVIEW用于对下位机参数读写、显示、报警等，从而实现了一套完整可靠的电阻采集监控系统。上位机和下位机通过Modbus通讯协议来进行数据的采集。
该系统具有使用方便、测量精确、稳定性高、可性强等优点，可以在很多领域应用，如温度、液位、压力等物理量的采集和监控。
关键字：89E516RD，MAX232，PCF8591,LABVIEW，Modbus协议
Abstract
The MODBUS protocol is a general application layer protocol applied to an electronic controller through which the controllers can communicate with each other via an Ethernet or serial communication network and other devices. Industrial controller networking also provides a convenient network management. MODBUS is a kind of industrial controller network protocol, it has become one of the mainstream industry standard. Interconnection of communication for different manufacturers of control equipment can be connected into the industrial network, to provide a centralized monitoring to facilitate.
LabVIEW is a program development environment developed by National Instruments (NI), similar to the C and BASIC development environments, but the significant difference between LabVIEW and other computer languages is that other computer languages use text-based language generation code , And LabVIEW uses a graphical editing language G program, the program is generated in the form of a block diagram. LabVIEW software is at the heart of the NI design platform and is ideal for developing measurement or control systems. The LabVIEW development environment integrates all the tools needed by engineers and scientists to quickly build applications that help engineers and scientists solve problems, increase productivity and innovate.
This design uses 89E516RD microcontroller, ADM2582 isolated RS-485 transceiver, the use of SIPEX SP3223EEY chip RS232 converter system, 89E516RD microcontroller as the next machine, the application of LABVIEW software prepared by the host computer monitoring program, the application of integrated microcontroller A / D Converter to complete the real-time potentiometer resistance analog acquisition and processing, and configuration king for the next crew parameters read and write, display, alarm, etc., in order to achieve a complete set of reliable resistance acquisition and monitoring system. The host computer and the lower computer through the Modbus communication protocol for data collection.
The system has the advantages of easy to use, accurate measurement, high stability and strong, and can be used in many fields such as temperature, liquid level, pressure and other physical quantity acquisition and monitoring.
Keywords: 89E516RD, MAX232, PCF8591, LABVIEW, Modbus protocol
目 录
