A Synchronization Method for Ethernet System Control and Communication

Abstract

The invention provides a method for synchronizing control and communication of an Ethernet system. The method comprises the steps of setting a state identification for a control task; itinerantly scanning a current time during the operation of a device, and respectively transmitting a periodic message and an aperiodic message within a periodic message time slice and an aperiodic message time slice; when the transmission of the periodic message and the aperiodic message is completed, judging whether the state identification of the control task is 1; if yes, namely meaning that the control task is not executed within a current macro period, executing the control task, and setting the state identification of the control task to be 0; and otherwise, namely meaning that the control task is executed within the current macro period, abandoning the execution of the control task. According to the method, the period synchronization of a user layer function block achieving a control function and link layer communication achieving a communication function can be achieved, the invalid execution of the function block and the invalid transmission of data can be avoided, and the operation efficiency and communication real-time performance of the system can be effectively improved. The method can be widely applied to the field of the industrial control.

Description

technical field [0001] The invention relates to the field of industrial control, in particular to a method for synchronizing control and communication of an Ethernet system. Background technique [0002] EPA (Ethernet for Plant Automation) factory automation Ethernet is a control system-oriented real-time Ethernet technology independently developed by China, which has been included in the fieldbus international standard IEC61158 and the real-time Ethernet international standard IEC61784. At present, EPA has been widely used in electric power, chemical industry, machinery, mining, petroleum and other fields. [0003] As a network control system, EPA realizes the distributed measurement and control under the network environment by delegating the control function to the function block of the field device. In the EPA system, multiple functional blocks that form a control loop are distributed in different EPA devices, and each functional block is connected to each other through ...

AI Technical Summary

Problems solved by technology

When the periodic message time slice and the aperiodic message time slice have not arrived, these messages cannot be transmitted in the queue of the link layer; and when the periodic message time slice and the aperiodic message time slice arrive, these messages will are sequentially transmitted to the same destination function block, causing old data to be overwritten by new data and not processed

[0004] It can be seen that in the prior art, the asynchrony of control and communication leads to invalid execution of function blocks and invalid transmission of data, which increases the calculation load and communication load of the system and seriously reduces the system performance.

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