IEEE1588 protocol time calibration method based on proportional integral algorithm

Abstract

The invention discloses an IEEE1588 protocol time calibration method based on a proportional integral algorithm. The IEEE1588 protocol time calibration method comprises the following steps: 1, calculating to obtain a time deviation value, and subtracting the system timestamp register (system_time) by the deviation value; 2, calculating a current time deviation value tb, storing the current time deviation value tb into a current time deviation value table, and calculating an integral value; 3, calculating a frequency compensation value; 4, setting an addend storage frequency compensation value of a register; 5, when the hardware crystal oscillator generates time counting, adding the updated value of the system timestamp register system time obtained in the step 1 to the counting period duration of the hardware crystal oscillator, and adding the value in the register address in the step 4 to obtain the current value of the system timestamp register system time, i.e., completing calibration of the system time. 7, receiving, by the system, the new IEEE1588 protocol and repeatedly executing the steps 2 to 5.

Description

technical field [0001] The invention belongs to the field of computer network communication, and in particular relates to an IEEE1588 protocol time calibration method based on a proportional integral algorithm. Background technique [0002] In the field of modern industrial manufacturing, a large system is often divided into multiple subsystems and sub-nodes, and all nodes work together, which requires the time of each node device to be consistent. Most of the hardware timekeeping is based on the counting method of the crystal oscillator. Since the frequency of each crystal oscillator cannot be exactly the same, this leads to inconsistencies in the time of different hardware devices. Therefore, this requires a certain mechanism to synchronize the time of the hardware devices on the network at regular intervals, and provide basic time synchronization services for the entire network. [0003] The Ethernet standard IEEE1588-2008 (version 2) stipulates an Ethernet-based time sy...

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Problems solved by technology

[0004] However, the IEEE1588 protocol does not give a specific time calibration method, usually directly subtracting the offset value from the system time to calibrate

The accuracy of this method is poor, and the clock jitter is large, which eventually makes the time synchronization accuracy worse

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