Response Time Driven Scheduling for Real-Time Programmable Logic Controllers with Network-Based I/O Systems

Abstract To reduce the response time determinately, this paper proposes a scheduling method for a programmable logic controller(PLC) with network-based I/O systems, assuming the multi-tasking facilities. A generalized architectural and behavioral model is developed to yield precise timing specifications, by which the proposed method schedules program execution and data transmission. A synchronization scheme, which enables the generated schedule to be realized on different processing elements with minimal hardware resources of PLC, is also suggested.

[1]  David Lorge Parnas,et al.  Scheduling Processes with Release Times, Deadlines, Precedence, and Exclusion Relations , 1990, IEEE Trans. Software Eng..

[2]  Wook Hyun Kwon,et al.  State Machine Based Deadline Analysis of a Programmable Controller for Real-Time Sequential Control Systems , 1995 .

[3]  Wook Hyun Kwon,et al.  Worst-case timing prediction of relay ladder logic by constraint analysis , 1996, Proceedings of 3rd International Workshop on Real-Time Computing Systems and Applications.

[4]  Ian G. Warnock.  Programmable Controllers: Operation and Application , 1988 .

[5]  Wook Hyun Kwon,et al.  Implementation of a parallel algorithm for event driven programmable controllers , 1993 .

[6]  H. Murakoshi,et al.  A high speed programmable controller based on Petri net , 1991, Proceedings IECON '91: 1991 International Conference on Industrial Electronics, Control and Instrumentation.

[7]  Wook Hyun Kwon,et al.  Scheduling algorithm for programmable logic controllers with remote I/Os , 1997, Proceedings Fourth International Workshop on Real-Time Computing Systems and Applications.

[8]  MengChu Zhou,et al.  Comparing ladder logic diagrams and Petri nets for sequence controller design through a discrete manufacturing system , 1994, IEEE Trans. Ind. Electron..