The Design Of Data Monitoring And Control System Based On USB And Lab VIEW

Scientific work often requires a qualitative understanding of the measured object, monitoringand control system is human to achieve the basic tools of measurement and control tasks，Researchand development of high-performance measurement and control system has high practical value.The bus interface is an important part of the measurement and control system，and theCommon use experiment observe and control system mainly use at the date gathering,dealing withshowing,storing of scientific research and teaching.USB(Unibersal Serial Bus) with its advantagesas plug-play, easy to use and high transmission rate,was more outstanding than the other bus. Theembedded processor of new generation based on Cortex core is being applied in industralmeasuremeng field widely due tu its cheap cost and excellent performance.Moreover，with thedevelopment of computer technology,Vittual Instrument(VI) based on PC computer has made grateprogress.Virtual instrument has become the development direction of measurement and controltechnology.The development and the application of Virtual instrument have provided the platformofr this system’srealization.Using LabVIEW to realize this fault diagnosis system can solve sometraditional instrument problems,such as the function lack and the using is not convenient and soon.This topic mainly makes use of the data measurement and control technology, USB technology,virtual instrument technology, to study based on USB bus and LabVIEW data measurement andcontrol system.This article elaborated the major design work from the overall system design, hardware design,software analysis and design and so on. The chip STM32based on Cortex-M3core is used for themain chip.Design multiple signal conditioning circuit and sensor circuit, realize the set ADconversion, data real-time transmission, real-time control functions in one data measurement andcontrol system.The system coule realize real-time data transmission to the PC through usbinterface,and could receive PC control command.The software is the core of the system,effecting the running of the system directly.Firstly, theauthor analyed the USB standard device class communication protocol and CDC (CommunicationsDevice Class).Then developed a USB CDC class communication protocol.Through LabVIEWVISA control to realize communication between PC and USB device. The application software isdeveloped by LabVIEW. The ADC embedded in STM32could realize multi-channel synchronousanalogue-to-digital conversions.The system could output the visualizated acquisition results,andrealize the real-time control.The combination of USB technology and LabVIEW is a good way torealize data acquisition,control and transmission.The system can realize analog singal acquisition,for examplethe light intensity, pressure, temperature, voltage, etc.At the same timecontrol eight-channel LED light up or go out.