Time Synchronization Protocol System and Synchronization Method Based on Chained Industrial Ethernet

Abstract

The invention discloses a time synchronization protocol system based on a chain industrial Ethernet and a synchronization method, and belongs to the technical field of communication. Measuring errors are decreased by the aid of a fixed-delay instant forwarding mechanism controller and a PLL (phase locking loop) frequency multiplication module output high-frequency clock, clock drift compensation is realized by the aid of a digital PLL clock drift compensation module, clock offset compensation is realized by the aid of a PI (proportional-integral) control ring clock offset compensation module, modules are obtained by the aid of a physical layer clock timestamp, and the influence of random physical link delay on clock timestamp acquiring accuracy is decreased. Random variables affecting chain Ethernet clock synchronization accuracy are limited or cut down, and the clock synchronization accuracy is improved.

Description

technical field [0001] The invention relates to a time synchronization protocol system and synchronization method, especially a chain network time synchronization system and synchronization method based on a fixed delay forwarding mechanism, separate compensation for clock drift and clock offset, and clock stamp physical layer acquisition, belonging to the field of communication technology . Background technique [0002] In recent years, due to its development, high transmission rate, low hardware cost and many other advantages, Ethernet has been continuously applied in the field of industrial field, and has replaced the industrial field bus as the second generation of industrial communication technology; at the same time, according to the processing and manufacturing of the industrial field Accuracy requirements require high synchronization accuracy between clocks at Ethernet distribution sites. How to ensure the synchronization accuracy of Ethernet has become one of the k...

AI Technical Summary

Problems solved by technology

[0005] However, the above-mentioned technologies adopt the method of real-time measurement and update dwell time when the transparent clock is used, which increases the load of the synchronization lumped frame, resulting in a significant extension of the synchronization time, and cannot fully integrate the synchronization process with repeated information communication, reducing the synchronization frequency. The measurement error of time information is large

Furthermore, when offset compensation is performed in the above technology, the drift and offset are not compensated separately. When the synchronization period is long, although the drift amount is negligible relative to the offset amount, it limits the further improvement of synchronization accuracy.

Finally, in the above technology, the time stamp acquisition is at the MAC layer, and cannot further advance to the physical layer (PHY), resulting in low precision of the acquired time stamp

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