Design And Implementation Of Pressure Transmitter Based On HART Protocol

With the development of microelectronics technology-. computer technology and communication skills, traditional analog pressure transmitter combined with field bus technology developed into field bus pressure transmitter. HART protocol is a kind of field bus protocol which is compatible with traditional Analog communication standard of 4-20mA. HART protocol can realize transfer Analog signal and digital single at the same time by loop carrier and the additional communication protocol can realize digital and intelligent management of meters.The system uses a C8051F410 MCU and HART modem chip, realized HART communication function. It meets on-site measurement of the pressure signal, display and communication needs. The system reduced overall system power consumption by using low-power components. Thus the system can use two-wire power supply simplifying the meter installation and improving the stability of the instrument. In order to solve the problem caused by the temperature characteristic of the pressure sensor, the thesis presents a fusion algorithm using polynomial fitting and three spline interpolation are combined, design a temperature compensation model, and realizes the function of temperature compensation in the software, reduced the measurement error. After testing, the design of the pressure transmitter can communicate with the host computer, the errors of zero and sensitivity are reduced after compensation of the working point.In this thesis, the design of two-wire interface scheme based on HART protocol pressure transmitter system, which uses two wire system interface program, low power consumption, temperature compensation effect is significant, overall high circuit integration, convenient field installation and debugging, has broad application prospects...