基于工业以太网的热电偶测温模块设计

Thermocouple Temperature Measurement Module Based on Industrial Ethernet

中文关键词:  工业以太网  热电偶  温度测量  嵌入式实时操作系统

英文关键词:industrial Ethernet  thermocouple  temperature measurement  embedded real time operating system

中文摘要:

      为了满足舰船推进监控报警系统扁平化、网络化的发展要求，基于Modbus/TCP工业以太网协议，设计了一种多通道高精度热电偶温度测量模块。模块硬件采用核心板+底板结构的标准化、模块化设计方案，核心板在STM32基础上集成了DM9000以太网通信电路和Flash存储电路，底板通过AD7793实现了高精度多通道热电偶测量电路。模块软件采用μC/OS II嵌入式实时系统进行多线程设计，网络核心通信线程通过裁剪LwIP+FreeModbus协议栈进行开发，冷端温度补偿算法和热电偶非线性校正算法都采用高精度最小二乘分段拟合实现。系统测试结果表明模块运行稳定且上位机网络通信稳定可靠，各通道温度测量精度高，具有较高的应用和推广价值。

英文摘要:

      In order to meet the development requirements of flattening and networking of the ships propulsion monitoring and alarm system,a multi channel high precision thermocouple temperature measurement module is designed based on the Modbus/TCP industrial Ethernet protocol.The modular hardware adopts standardized and modular design scheme of core board+backplane structure.The core board integrates DM9000 Ethernet communication circuit and flashing storage circuit with STM32 as the core.The backplane implements a high precision multi channel thermocouple measurement circuit with AD7793.The module software adopts μC/OS II embedded system for multi thread design,the network core communication thread is developed by LwIP protocol stack designand FreeModbus protocol stack,and both the cold junction temperature compensation algorithm and thermocouple nonlinear correction algorithm are implemented by high precision least squares segment fitting.The system test results show that the module runs stably and the host computer network communication is stable and reliable,the temperature measurement accuracy of each channel is high,which has high application and promotion value.