毕业设计（论文）-基于RS485现场总线的温度采集模块的设计.doc

河 南 工 业 职 业 技 术 学 院 Henan Polytechnic institute 毕业设计（论文） 题目：温度采集器 班级：生产过程自动化0901 姓名： 指导老师： 摘 要 温度是现代工业生产过程中的一个要参数, 在生产过程中常需对温度进行检测和监控、。，Abstract Temperature is the process of modern industrial production as an important parameter, in the production process often required to detect and monitor the temperature, especially in the electricity, chemical industry and other large enterprises, automation of production processes often require dozens of monitoring and measuring the temperature parameters. Production in some special occasions (such as printing and dyeing and refining), temperature measurement and control parameters directly affect the accuracy of follow-up to the quality of the product. In this paper, based on the temperature RS485 fieldbus module design method of collection. Thermal resistance with temperature changes in the resistance of different signals, resistance constant current signal into the analog voltage signal, single-chip multi-channel analog switches internal circuitry of the analog signal acquisition, A / D converter module of the signal collected analog-to-digital conversion, to convert digital signals received, respectively, in accordance with the sequence into single-chip, single-chip RS485 fieldbus through with PC-articulated. As the resistance value and temperature is non-linear relationship between, in order to improve the measurement accuracy to overcome the non-linear error, reducing the index storage table, the use of quadratic interpolation algorithm for calculating the temperature value, so that the temperature resolution of 0.05 ℃ , temperature measurement accuracy of better than 0.1 ℃. Single-chip microcomputer through fieldbus temperature in order to be able to MODBUS agreement sent to the PC, the realization of the Industrial Fieldbus computer for centralized ma