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Improvement of Memory Efficiency for Alternative Sequence in Process Control System Described by SFC

SFC로 설계된 공정제어에서 선택시퀀스의 메모리효율향상

  • 유정봉 (공주대학교 전기전자제어공학부)
  • Received : 2010.01.12
  • Accepted : 2010.03.04
  • Published : 2010.05.31

Abstract

When we design the control system used Programmable Logic Controller(PLC) by Sequential Function Chart(SFC), if we use a SFC, it is easy to know the sequential flow of control, to maintenance the controller and to describe a program. We program a SFC by a unique sequence, an alternative sequence and a parallel sequence. If we program a SFC by a alternative sequence, the memory size of a alternative sequence must be larger than the memory size of a unique sequence. Therefore this thesis show an efficient method to reduce a memory size and we confirmed its feasibility through actual example.

PLC 제어 시스템은 SFC 언어를 사용하여 설계할 경우, SFC 언어를 사용하면 제어의 흐름을 이해하기 쉽고, 유지보수가 용이하며 프로그램의 기술성이 뛰어나다. SFC 언어는 단일 시퀀스, 선택 시퀀스, 병렬 시퀀스로 나누어지며, 선택 시퀀스로 프로그래밍 하면 단일 시퀀스로 프로그램할 때보다 메모리의 크기가 커져야 한다. 본 논문에서는 선택 시퀀스의 기능을 단일 시퀀스로 구현하여 메모리의 크기를 줄여서 메모리의 효율을 향상시키는 방법을 제시하고, 실례를 통해 타당성을 확인하였다.

Keywords

References

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