Application of USB in data collection

PC standard USB ( Universal Serial Bus ) supplies advantages for multi-access data collec-tion.The specialties of USB are summarized and a data collection system based on it is introducd ,which uses the I/O ports of single-chip microprocessor and generates needed signals via3-step driving expansion and de-coding.The data from448binary channels and16analog channels are successfully collected using USB under control of single-chip microprocessor.