The Design Of Multi-channel Data Acquisition System Based On FPGA

Data acquisition is the basis of scientific research.How to design multi-channel,high sampling rate,high transmission rate,high accuracy and high versatility data acquisition system has always been the development direction of data acquisition system.This paper focuses on the limitations of the commonly used multi-channel data acquisition card applications.By studying the theoretical basis and drawing on the mature design scheme,this paper studies and designs the multi-channel data acquisition system based on FPGA.By comparing several design methods,choose the appropriate design to achieve multi-channel,high-precision data acquisition.This paper makes an in-depth study on PCI bus technology by comparing various data interface schemes,and uses PCI bus interface chip PCI9054 to realize data transmission.According to the design experience,the system digital logic scale is estimated,and the Cyclone IV series EP4CE75 is selected as the main control chip of the system.By designing FPGA digital logic,multi-channel signal acquisition and digital input and output interface control are realized;the acquisition card driver and host computer application software are designed to complete data transmission,processing,display and storage.Measurement accuracy is the basic requirement of data acquisition.By establishing a model to analyze the source of system error,curve fitting and neural network algorithm are used to realize self-calibration of system error and improve system test accuracy.The data acquisition system designed in this paper can collect 48 single-ended analog signals or 24 differential analog signals.The acquisition accuracy is 16 bits,the sampling depth can reach 8M×16bits;48 digital input and output interfaces are provided for control or digital signals.Frequency measurement.The developed upper computer application software can realize the control of the acquisition card and real-time data processing.Through the whole machine test,the performance of the acquisition system meets the design requirements.