Data Acquisition And Processing Platform Based On DSP And PCI Bus

Date acquisition card is widely used in data acquisition and measurement. The difference between this card and others normal data acquisition card is its high performance with the help of floating point DSP. The DSP makes this card have a high performance not only in data acquisition but data calculating and processing. The introduction of PCI bus technology improves the data throughput between the data acquisition card and PCs, eliminates the bottleneck in this section.This paper is mainly discusses the design of a general data acquisition card with maximum acquisition rate at 5M. This card is mainly used to analyse collectted in frequency domain. The main working process is:adjusting the analog signal, using ADS1605 to convert the analog signal into digital signal with 16bit resolution.with the control of CPLD,the data is collected into DSP. And then, the DSP will do some algorithm, such as FFT. The PCI interfacing chip will read the spectrum and transmit these data to PCs. The program we had designed with Labwindows will display the spectrum plot and some useful information.The main goal of this project is to design a data acquisition card to detect the grain diameter of phytoplankton under the water and measure the density of the phytoplankton.In the acquisition card part,we need to collect the fluorescent signal and doppler signal. The phytoplankton under the water doesnot show up regularly, so the emerging of both signals are unpredictable. In this system,we should collect double channels signal and detect the front 2K signal. If the data we calculated is greater than the threshold, the DSP will continue to collect the following 6K signals. So we can get the whole envelope curve of both signals. Because we need to make frequency analysis work on the both channels, we had used DSP to complete this work to make sure a high efficiency.What's more, this system introduces a double channels data acquisition proposal in the broad sense. Thanks to the DSP designed in this board, this card can be widely used in the future high speed acoustic and light signals acqusition situation.