Data Acquisition And Data Processing In A System Diagnosis

Data Acquisition And Data Processing In A System DiagnosisThis paper is resulted from a work of system diagnosis, it mainly demonstrates the data acquisition and data processing techniques and algorithms of the programs dedicated to sampling, data transferring and data analysis.In the hardware description, it introduces the PC/104 standard , a PC/104 format CPU module and a PC/104 multi-functional module for data acquisition. This multi-functional module is very powerful and integrated, it has 32 analog input channels, 24 digital input/output channels, three 16 bit counters/timers and provides flexible approaches of multi-channel sampling and of digital I/O operations. Especially it allows various types of interruptions of external digital input, timer output and A/D conversion, each type of interruption has its own role in the signal measurement or in exact pace control, its FIFO buffer function makes it possible to work at the sampling rate of 200K samples per second without carrying over-burden interruption rate, its LATCH type external interrupt request along with its high frequency clock makes a precise locating of pulse edges possible. All its properties make it best suitable for the system diagnosis which involves examining 13 analog signals, detecting several digital signals, issuing the required instructions at an exact pace and sampling many analog signals simultaneously.In the parts of software discussion, it presents the primary algorithms of some fundamental functions in C language, these functions are developed for digital I/O operations, interruption management, tinier management, precise clock generator. A/D conversion, data transferring and some calculations. And also, it introduces the powerful tools of MATLAB and demonstrates some MATLAB programs for spectral property analysis, digital filter design, digital filtering, signal extracting, noise eliminating, parameter calculating and some applications.The conclusions of the paper present an analysis of the results of the diagnosis and points out some work worth doing next.