Implementation of the USB interface in the instrumentation for sound and vibration measurements and analysis

The USB (universal serial bus) interface is now commonly used in computer hardware. It assures asynchronous serial data transmission with the speed which is much bigger than that in RS 232 interface. The essay of an USB implementation in the unit intended for sound and vibration measurements and analysis is presented. The aim of the USB interface implementation was to assure fast data transmission between the unit and a PC. The USBN9602 chip of National Semiconductors was used as an interface controller. The software was developed in the measurement unit and in a PC for testing the application. The different modes of data transmission were tested. The achieved results of the tests performed in different operating systems are presented. The conclusions concerning required modification of the implementation in order to achieve faster transmission are drawn.