基于HART协议的数据采集与通信系统设计

摘要信息化时代，数据通信的重要性不言而喻。HART的工程优势体现为与现有仪表实际应用的良好兼容性，因此现场总线温度变送器取代传统的温度变送器已成必然。对基于HART 协议的数据采集以及通信系统的研究具有现实意义。本论文论述了将单片机技术和HART 通信技术引入温度变送器中，实现温度变送器的数据采集、数据处理、数据通信、远程管理、远程监控等功能。温度变送器主要有数据采集和通信两个模块。数据采集模块是利用单片机对温度传感器采集的数据进行存储和处理，使之符合通信模块数据格式的要求，然后再送至通信模块进行通信。通信模块首先通过AD421 将数据转换成4~20mA的模拟电流信号，然后叠加上HT2012调制的数字信号进行通信。本论文对单片机技术和HART协议做了全面的介绍和分析,并从硬件和软件两个方面分析和论述关于温度变送器的设计。关键词：单片机；数据采集；HART 协议；温度变送器9607
Abstract
When we enter the information age, the data communication is becoming more
and more important. The engineering advantage of Hart protocol is having the good
compatibility with the present instruments. So it is certain that the field bus
temperature transmitter should take place of traditional temperature transmitter. The
research and development of HART protocol smart temperature transmitter has real
significance.
This project discussed something about applying the technology of single-chip
computer and HART communications protocol to temperature transmitter, to realize
temperature transmitter’s data acquisition, data processing, data communications,
remote management, and remote control. The temperature transmitter mainly includes
the data acquisition module and communication module. Data acquisition module：to
use the single-chip computer to store and process the data from temperature
transducer so that it meets the requirements of data communication module. And then
to sent it to communication module for data transmission. Communication module: to
use AD421 to convert the data to 4~20mA analog signal. And then to combine the
modulated digital signals by HT2012 to communicate.
The project gave a comprehensive analysis of technology of single-chip
computer and HART protocol standard, and then analyzed the design of temperature
transducer from both hardware and software.

Keywords: Single-chip computer; data acquisition ; HART Protocol; temperature
transducer 目录
1 绪论 . 1
1.1数据采集的发展   1
1.2 HART技术的发展 . 1
1.3目的和意义 . 2
1.4论文主要内容. 2
2.HART 协议简介   3
2.1概述 . 3
2.2 HART通信结构的OSI参考模型 .. 5
2.2.1物理层 . 5
2.2.2数据链路层 .. 6
2.2.3应用层 . 7
2.3各层之间的关系   9
3.硬件设计 .. 9
3.1总体设计框图. 9
3.2数据采集系统设计   10
3.2.1智能温度传感器DS18B20   10
3.2.2 单片机 .. 11
3.3 HART通信系统设计 . 14
3.3.1 AD421芯片 14
3.3.2 HT2012芯片 . 16
3.4与主机之间的接口电路设计 .. 21
3.4.1串口通信RS232 . 21
3.4.2MAX232芯片简介 . 22
3.4.3接口电路图   23
4.软件设计 23
4.1 监控程序   23
4.2测控程序   24
4.2.1   数据采集和转换 . 24
4.2.2   数据输出 . 24 基于HART协议的数据采集与通信系统设计:http://www.youerw.com/tongxin/lunwen_8399.html