目录
摘要……..........................................................................................................................I
Abstract...........................................................................................................................II
第 1 章 绪论...................................................................................................................1
1.1 课题背景..............................................................................................................1
1.2 智能变送器的现状..............................................................................................2
1.3 现场信号通信的发展概况..................................................................................4
1.4 本论文的主要工作..............................................................................................6
第 2 章 硬件电路设计...................................................................................................8
2.1 单片机选择..........................................................................................................9
2.2 输入信号增益自调节电路设计..........................................................................9
2.3 模—数转换器选择及接口电路设计................................................................11
2.3.1 TLC2543C 简介...........................................................................................11
2.3.2 TLC2543C 的主要性能...............................................................................12
2.3.3 TLC2543C 的转换过程...............................................................................13
2.4 数—模转换器接口电路设计............................................................................15
2.5 V/I 变换电路设计...............................................................................................15
2.6 复位及运行监视电路设计................................................................................16
2.7 RS—485 总线接口电路设计 .............................................................................18
2.8 显示器接口电路设计........................................................................................19
2.9 键盘接口电路设计............................................................................................19
2.10 电源..................................................................................................................20
2.11 本章小结..........................................................................................................20
第 3 章 应用软件设计.................................................................................................21
3.1 监控程序模块....................................................................................................21
3.2 输入信号增益自调节模块................................................................................22
3.3 数据采集和处理模块........................................................................................22
3.4 通信模块设计....................................................................................................23
3.4.1 串行通信接口的基本任务.........................................................................24
3.4.2 RS—485 简介和串行通信协议的实现 ......................................................24
3.5 通信模块设计....................................................................................................29
3.6 键盘模块的设计................................................................................................29
3.7 软件抗干扰的设计............................................................................................30
3.8 本章小结............................................................................................................31
结论...............................................................................................................................32
致谢...............................................................................................................................33
参考文献.......................................................................................................................34
