IEC 61499 functional block modeling method for determining calculation time sequence

Abstract

The invention relates to an IEC 61499 functional block modeling method capable of ensuring calculation time sequence determinacy. The method comprises the following steps of: redefining an event interface of a functional block for defining an event as an event structure body containing a timestamp; adding a time sequence management module of a function block to the arrival event, analyzing the arrived local event, arranging the events according to the time sequence, and ensuring that the events in the event queue are responded according to the determined time sequence; and adding an algorithmexecution management module and using for defining algorithm execution time constraints and an overtime response processing algorithm interface, managing an ECC execution response algorithm and monitoring a program execution state. According to the method, the determinacy of cooperative computing of the distributed system is guaranteed by extending the IEC 61499 basic function blocks, and the function block structure can guarantee the consistency of event execution time sequences and the determinacy of event response algorithm execution in the distributed system with high concurrency of asynchronous events.

Description

technical field [0001] The invention relates to the technical field of industrial automation and computer control, in particular to the industrial distributed system programming standard IEC 61499 and the programming language of the function block, specifically a method for modeling the IEC 61499 function block for determining the calculation sequence. Background technique [0002] With the development of flexible manufacturing, it has become a trend to realize the response of the manufacturing system to the dynamic demand through the collaborative computing of each manufacturing unit. The IEC 61499 standard proposes the function block as the core content for the industrial process measurement and control system (IPMCS), emphasizing the distributed software programming method through the combination of function blocks to complete the cooperative operation. The IEC 61499 function block responds to various events in the system in an event-driven manner and uses an execution co...

AI Technical Summary

Problems solved by technology

During the operation of a distributed system, the high concurrency of computing tasks on a large number of devices may lead to multiple events in the same time slot, and these events have a sequence in time sequence. Due to the asynchronous clocks in the distributed system and the network delay Due to the dynamic changes of the task, the execution sequence is not executed according to the timing of the task, resulting in system uncertainty

In addition, errors may occur during the execution of the event response program, and the execution of the program falls into an infinite loop or an unknown state, resulting in uncertain situations such as no output or wrong results.

The IEC 61499 function block only emphasizes the advantages of event-driven fast response and asynchronous flexibility. It lacks strict definitions for the correct response of event timing and the deterministic execution of response algorithms, and it is difficult to guarantee the determinism of distributed system collaborative computing.

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