Software Design Of USB Portable Data Acquisition System

Data acquisition is used to automaticlly collect electric or non-electric signals from device under test. As a mean of control, DAQ is widely used in automated monitoring,measurement and control, and aerospace test. This thesis is about the design of DAQ based on USB bus. USB bus has features such as Plug and play, hot swappable and high speed.The USB portable DAQ has many features that make it ideal for digital waveform acquisitions. These include flexible memory sizes, voltage levels, diverse acquisition triggering choices, powerful data visualization programming features, and extensive expansion and integration capabilities.This thesis descibe the design of software of USB portable DAQ system, mainly includes firmware, device driver, instrument driver, and man-machine interface program.We choose the EZ-USB FX2 series chip for USB interface. Using its firmware framework can quickly complete the firmware design. Using its GPIF mode can quickly upload data to the host computer. The environment for designing device driver is DriverStudio. Using DriverStudio can quickly design a device driver in line with Windows WDM driver model. By calling WIN32 functions, we build the communication between application and driver. Pack the functionalities according to the requirement and generate dynamic link library file. The DLL file is called instrument driver. Using CVI development environment, by calling the instrument driver, build the man-machine interface of this equipment. The man-machine interface make the operator more convenient. Finally,joint the hardware part and debug, analyze and solve problems encountered during debugging, and compete all the functions of this equipment.After several test, this USB portable DAQ system can easily and quickly complete data acquisition task. The goal of this design has been achieved with high practical value.