Clock synchronization method and system

Abstract

The embodiment of the invention provides a clock synchronization method and a system. The clock synchronization method comprises the following steps: acquiring synchronism deviation between a master clock and a slave clock sent from a clock, and acquiring a synchronism deviation reference value between the master clock and the slave clock according to the synchronism deviation between the master clock and the slave clock; acquiring a synchronism deviation reference value between the master clock and the slave clock in unit time according to the synchronism deviation reference value between the master clock and the slave clock; acquiring the maximum synchronism deviation allowed between the master clock and the slave clock according to the synchronism accuracy requirement between the master clock and the slave clock; calculating the minimum value of synchronization frequency between the master clock and the slave clock according to the synchronism deviation reference value between the master clock and the slave clock in the unit time and the maximum synchronism deviation allowed between the master clock and the slave clock; and taking a value not less than the minimum value of the synchronization frequency between the master clock and the slave clock as a synchronization frequency value of the master clock, and carrying out clock synchronization. The embodiment of the invention reduce the synchronism deviation between the master clock and the slave clock and make the synchronism deviation between the master clock and the slave clock meet the accuracy requirement between the master clock and the slave clock of the system.

Description

technical field [0001] The invention relates to the technical field of industrial communication, in particular to a clock synchronization method and system. Background technique [0002] As networks are applied to industrial control systems, clock synchronization technology plays an increasingly important role in industrial control systems, and different industrial applications have different requirements for clock synchronization accuracy between devices. At present, the most commonly used clock synchronization method in industrial control systems is: under the master-slave network structure, the clock of the master device in the network system broadcasts the clock of the master device to the clock of the slave device on a regular basis, and all slave devices in the network system receive the time of the master device. Update its own clock after its own time, so as to realize the synchronization of all clocks in the network system. [0003] However, in an industrial contro...

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Problems solved by technology

[0003] However, in an industrial control system, after the master-slave devices achieve clock synchronization, the clock synchronization deviation between the master-slave devices increases due to the deviation of the crystal oscillator frequency between the master-slave devices, which may cause the clock synchronization deviation between the master-slave devices, that is, the master The synchronization deviation between the slave clocks cannot meet the synchronization accuracy requirements between the master and slave clocks

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