The Development Of An Ultralow-power Smart Valve Positioner Based On The Msp430

Valve positioner is a complementary instrument used together with pneumatic actuators. Its basic function is to receive the output signal of the regulator and to control the pneumatic actuator with its output signal. Therefore the positioner and the actuator form a closed loop. Electrical valve positioner came into being along with the electrization of work condition. Instead of the 20~100kPa pneumatic signal, a 4~20mA current signal could be used as the input signal of the valve positioner. The development of digital valve positioner and field bus, has brought profound changes into the automatic manufacture, and represents the direction of the development of pneumatic actuator technology.The key part of this issue is to achieve the goal of ultralow-power consumption, HART communication and valve stroke control for the development of an ultralow-power smart valve positioner based on the MSP430. In the research, the following achievements have been made.(1) An ultralow-power circuit system is designed, including power circuit, sampling circuit, ultralow-power MSP430 MCU system, I/P control circuit.(2) An I/P conversion unit is designed.(3) The circuit of HART communication is designed, including receiver circuit and output circuit.(4) The system software package with modularity is developed, including control program, LCD display program, keyboard program, protection with power-off program.As the rapid development of field bus technology, automatic control system becomes more and more"intelligent, digital, informative, and decentralized". It is an inevitable trend for Valve positioner which is the terminal control equipment of related industries to become more and more digital and intelligent in the future. The valve positioner researched in this paper is based on the current situation of domestic industry, and meets the requirements of the development of modern industry.