基于单片机的通用智能测控系统--下位机部分毕业设计论文

内蒙古科技大学毕业设计说明书（毕业论文）

基于单片机的智能通用测控系统设计——下位机部分

摘 要

基于微处理器的智能测控系统设计，已经成为广大电子设计工程师或相关领域设计者关注的热点。由于智能测控系统面向不同的应用领域，采用不同的实现途径，使用不同的开发环境，因此其设计调试过程往往是复杂而且痛苦的。本设计主要介绍了基于单片机的通用测控系统，能够实现采集4~20mA模拟量和开关量并输出4~20mA的模拟量和开关量，并将数据实时地传回上位机等功能。

该系统硬件部分详细论述了由AT89C51系列单片机实现的智能测控系统，采用光电耦合器件、TLC0832模数转换器、I/V变换电路等部件实现前向通道数据采集功能以及采用DAC0832数模转换器和VI变换电路实现后向通道数据的输出功能，同时该系统采用了RS485总线实现上位机和下位机的通信。本系统是和上位机联机调试的,由于缺乏硬件不能进行在线调试，但是结果经过论证符合实际要求。该系统能够应用于一般工业测控要求的场合，系统具有低耗能、结构简单、可靠性高、速度快、连接方便等特点。

智能测控系统是工业生产发展的必然要求，也是计算机及网络技术在工业领域中的控制功能进一步加强的必要条件，因此本次设计就更具有了讨论和研究的现实意义。

关键词：单片机；转换电路；串行接口；测控系统；变换器

V

内蒙古科技大学毕业设计说明书（毕业论文）

Based on Single-chip Compute intelligent general observation

and controlsystem design

- -The auxilibary compute

Abstract

Based on the microprocessor intelligent measurement and control system design, already became the hot spot to which general electron project engineer or the correlation domain designer paid attention.Because of the intelligent measurement and control system facing different application domain, using different realizing way, using different developing environment, the debugging process often is complex moreover than pain. This design mainly introduces the general measurement and control system which is based on the Single-chip Compute. It can gather 4~20 mA digital signal and the switch signal, and output 4~20 mA digital signal and the switch signal, and tranmit the data to PC part.

This hardware part of the system in detail introducing the intelligent measurement and control system which realized by AT89C51 series Single-chip Compute, uses the part such as the photoelectricity coupled apparatus, the TLC0832 A/D converter and the I/V Switching circuit realize the functions of the front channel data acquisition as well as uses the DAC0832 D/A converter and V/I Switching circuit realize the function of the backward channel data output, simultaneously it uses the RS485 main line realize the correspondence between the PC part and the auxilibary compute. This system is on-line debugged with the PC part, because of lacking the hardware not to be able to carry on the online debugging, but the result proofs to be the actual requirement. This system can be applied in the general industry measurement and control request situation, it has the characteristics of energy lowly, the structure simply, the reliability high, the speed quickly, connection convenience and so on.

VI

内蒙古科技大学毕业设计说明书（毕业论文）

Intelligent measurement and control system is the necessary requirement of industrial production and development, as well as the necessary conditions of computer and network technology in the field of industrial control function to further strengthen. It is necessary to discuss and study, at the same time it has much practical significance.

Key words: Single-chip Compute; Converter; Serial interface; Measurement and control system; Switching circuit

VII

内蒙古科技大学毕业设计说明书（毕业论文）

目 录

摘 要 ................................................................................................................................... V Abstract .................................................................................................................................... VI 第一章 引 言 .......................................................................................................................... 1

1.1 概述 ............................................................................................................................. 1 1.2 智能测控系统的功能 ................................................................................................. 1 1.3 测控系统的发展趋势 ................................................................................................. 1 1.4 单片机的技术发展史 ................................................................................................. 2 第二章 系统方案设计 .............................................................................................................. 4

2.1 设计内容 ..................................................................................................................... 4 2.2 系统组成 ..................................................................................................................... 4

2.2.1 数据采集模块 .................................................................................................. 4 2.2.2 串口通信模块 .................................................................................................. 5 2.2.3 数据输出模块 .................................................................................................. 5

第三章 方案设计应注意的问题 .............................................................................................. 6

3.1 总体设计（功能设计） ............................................................................................. 6 3.2 转换器设计 ................................................................................................................. 6 3.3 可靠性设计 ................................................................................................................. 8

3.3.1 要注意简化电路结构 ...................................................................................... 8 3.3.2 采用成熟技术和通用器件 .............................................................................. 8 3.4 成本设计 ..................................................................................................................... 8 第四章 系统硬件设计 .............................................................................................................. 9

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