The Research And Implementation Of The Temperature Transmitter Based On The PROFIBUS Fieldbus

The signal of 4-20 mA or 24 VDC,with the line of point to point,used in traditional field measurement and control device,has a limited amount of information.It is difficult to achieve the information exchange between the equipments and the outside world,restricts seriously the integration of the enterprise information and the implementation of integrated automation.With the development of network information technology and automation technology,fieldbus technology has made great progress,but also put forward higher requirements for transmission of signals between devices.The Profibus-DP is the most important open field bus system.Compared with other monitoring systems,the system has the advantages of simple structure,strong anti-interference ability,fast communication speed.In the field of industrial applications,each machine working well or not is related to the safe operation of the whole system,the instrument operation temperature is an important part as the evaluation system is normal.Thus,the temperature of the industrial field equipment transmitted to the monitoring platform of temperature parameters timely and accurately is necessary.In this paper,it studies the basic characteristics and communication protocol of the Profibus-DP Fieldbus based on the Profibus technology in refer to the relevant literature,and presents the superiority of the Profibus technology in the daily manufacture,investigation the method of the collection of temperature data,processing,transmission,and the effect on the measuring accuracy.This paper focuses on the hardware architecture of STM32F103VCT6 microcontrollers as the core design,design temperature detection module based on MAX31865 and MAX31855 chip,achieve the Profibus-DP slave station agreement with DP chip VPC3+C,completed design of the hardware and software.The intelligent temperature transmitter can integrate the discrete sampling point of the actual production,and transfer the collected temperature data to the main station platform to achieve the purpose of real-time monitoring.The intelligent temperature transmitter,applicable to a variety of thermal resistance and thermocouple sensor,with a wide measuring range and cheap cost,has a great practical value.