Research And Implementation Of Usbtmc Specification About Universal Test Instrument

USB（Universal Serial BUS）is a new interface which connects peripheral devicesto the computer. It has been widely used in all over the world because of its own uniqueadvantages. With the development of computer technology, the combination of Test andMeasurement Technology and Computer Technology has become a trend. To followingthe trend, the USB Union made the USBTMC (Universal Serial Bus Test andMeasurement Class Specification) standards to standardize the application of USB intest instruments further.The main task of this project is to study and achieve USBTMC protocol standard,including researching USBTMC protocol standards, selecting the appropriate solution,designing the device driver and host program which meet USBTMC protocol. The maincontents are as below:1．The basic content of the protocol was studied.Those contents about USBuniversal protocol, USB system architecture, USB devices structure, USB data transfertypes, USB data structure and USB data transfer process were studied. On the basis ofunderstanding USB’s basic principles, the basic content of USBTMC with transfermode, data format, transfer process were explained.2．The scheme was Selected and analyzed.Between the kernel driver and the usermode driver, according to their advantages and disadvantages, a development scheme ofdevice driver program which meet USBTMC protocol was chosen. Then the feasibilityof this solution was analyzed in detail. At last, development scheme of host driverwhich meet USBTMC protocol should be determined with full consideration of shortingthe development cycle and improving portabilith. And the scheme also should beanalyzed.3．The drivers were programed.Considering kinds of transmission modes used inUSB protocol and USBTMC protocol, as well as the characteristics of user mode driver,the programming idea which was used to design program of the device driver and hostdriver of meeting USBTMC protocol was decided and the programs were completed.4．The dirvers were tested.According to requirements of this project, software test method was confirmed, and the function of the host driver and the device driver weretested. Finally, the solutions of the problems that encountered during the developmentand test process were put forward.According to the test result, the drivers based on this project meets the USBTMCprotocol and can perform all functions that the USBTMC requests.