A high-precision timing method for data acquisition card

Abstract

The invention discloses a high-precision timing method for a data acquisition card. Firstly, a GPS timing module performs signal connection with a host computer through a serial port, absolute time istransmitted to the host computer, and second pulse signals are transmitted to the data acquisition card; then, the data acquisition card is in signal connection with the host computer through a PCIebus, and data are continuously uploaded to the host computer according to N sampling points of each packet of data; the host computer calculates the sampling number between two second pulses accordingto the data uploaded by the data acquisition card, the deviation caused by crystal oscillator errors is eliminated, multiple times of averaging are carried out, errors caused by second pulse jitter are eliminated, an accurate sampling rate is solved, and thus, accurate timing for a sampling point of each packet of data can be completed. According to the high-precision timing method for the data acquisition card disclosed in the invention, a high-precision time stamp is provided for the data waveform acquired by the data acquisition card, especially in the case of high-speed sampling, and high-precision time dimension information is provided.

Description

technical field [0001] The invention belongs to the field of digital signal processing, in particular to a high-precision timing method for a data acquisition card. Background technique [0002] At present, data acquisition cards are widely used in various industrial sites to automatically collect non-electric or electric signals from analog and digital units under test such as sensors or other equipment under test, and send them to the host computer for analysis and processing. The data acquisition system is a flexible and user-defined measurement system combined with measurement software and hardware products based on computers or other special test platforms. At present, more and more application scenarios require data acquisition cards to complete data acquisition, and at the same time provide high-precision time stamps for data. Some data acquisition cards have time stamp functions, or use dedicated timing modules. Both of the above two methods increase hardware cost. ...

AI Technical Summary

Problems solved by technology

At present, more and more application scenarios require data acquisition cards to complete data acquisition, and at the same time provide high-precision time stamps for data. Some data acquisition cards have time stamp functions, or use dedicated timing modules. Both of the above two methods increase hardware cost

In addition, the time accuracy of the acquisition cards with time stamp function on the market is not high, and the accuracy can only reach 5 microseconds

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