Time interval measuring instrument based on FPGA

Abstract

The invention provides a time interval measuring instrument based on FPGA. The time interval measuring instrument is designed into a virtual instrument by taking a PXI interface as a platform; a PXI system can be inserted with a plurality of PXI cards; each card carries out time interval measurement to signals of one initial channel and a plurality of stopping channels; simultaneously the pulse width of stop pulse is measured. The time interval measuring instrument utilizes phase-locked loop frequency doubling and time phase-splitting technology so that the measuring resolution can be up to 1ns and the measuring range can be up to 20ns to 200ms. As the virtual instrument structure is adopted, a PXI platform and a computer are combined to form an automatic measuring system; and the time interval measuring instrument has the advantages of simple structure, convenient use, high reliability, strong expandability and high measuring efficiency.

Description

technical field [0001] The invention belongs to the technical field of data acquisition, and in particular relates to an FPGA-based time interval measuring instrument for measuring the time interval between a start pulse and multiple stop pulses and the pulse width of the stop pulses. Background technique [0002] Precision time interval measurement is widely used in various scientific experiments. Instruments used for time interval measurement include general-purpose counters, digital storage oscilloscopes, and multi-channel time interval measuring instruments have their own characteristics. General-purpose counters are expensive, inconvenient to operate, and have few measurement channels, and have gradually withdrawn from the occasion of time interval measurement. Oscilloscopes have always occupied the main position in electronic measuring instruments, but when the number of independent test points reaches dozens or hundreds, the number of channels of the oscilloscope is t...

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Problems solved by technology

However, with the development of technology and the higher and higher requirements of experiments, the time interval measuring instrument still needs further improvement. First, its serial interface cannot meet the requirements of test system automation; second, most of the circuit parts are discrete components. The integration level is not high, so the structure is complicated, the installation is inconvenient, and the reliability needs to be improved; the third is that the chassis is too heavy, the strength is not enough, the load-bearing capacity is poor, and it is inconvenient to disassemble, which brings difficulties to maintenance

[0003] Chinese Patent Literature Publication No. 101013304A discloses a patent application technology named "A PCI Card for High-precision Time Interval Measurement". This technology has fewer measurement channels and poor scalability due to the use of a dedicated chip; due to the use of PCI as the data interface , poor reliability and anti-interference, not suitable for occasions with high measurement requirements such as high reliability and multi-channel

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