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A Method for Implementing a Safety Control System Based on Its Separation into Safety-Related and Non-Safety-Related Parts

  • Toshihito Shirai
  • Masayoshi Sakai
  • Koichi Futsuhara
  • Masao Mukaidono
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1667)

Abstract

International safety standards recommend that control systems should be separated into safety-related and non-safety-related parts. The control circuit is required to have such an interlock function that the control output of the safety-related part gives permission to the control output of the non-safety-related part. This paper describes the methods of separating and combining the safety-related and non-safety related parts in Chapter 2. In Chapter 3, a configuration example of the control circuit for producing a control output is presented. The control circuit is constructed by two fail-safe techniques, or dynamic fail-safe signal processing and voltage-above-supply-voltage processing. The proposed control circuit has such a fail-safe characteristic that it produces no output when the frequent check of its functioning detects a failure in any of its elements. An interlock device constructed by using the two fail-safe processing techniques and containing high-output semiconductor switching elements is shown.

Keywords

Supply Voltage Control Circuit Control Output Related Part Switching Element 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    ISO/IEC DIS 13849-1, Safety of machinery: Safety-related parts of control systems (1997).Google Scholar
  2. 2.
    Draft IEC 1508, Functional safety: Safety-related systems (1995).Google Scholar
  3. 3.
    PrEN 50100-1, Safety of machinery: Electro-sensitive protective devices (1994).Google Scholar
  4. 4.
    K. Futsuhara, N. Sugimoto and M. Mukaidono: A Method of Constructing Safety Device with Consideration of Noise-Induced Errors, Proc. of 2nd Int. Conf. on Human Aspects of Advanced Manufacturing and Hybrid Automation, pp. 921–928 (Aug. 1990).Google Scholar
  5. 5.
    M. Kato, M. Sakai, K. Jinkawa, K. Futsuhara and M. Mukaidono: LSI Implementation and Safety Verification of Window Comparator Used in Fail-Safe Multiple-Valued Logic Operations, IEICE Trans. Electron., Vol. E76-C, No. 3, pp. 419–427 (Mar. 1993).Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • Toshihito Shirai
    • 1
  • Masayoshi Sakai
    • 1
  • Koichi Futsuhara
    • 1
  • Masao Mukaidono
    • 2
  1. 1.Nippon Signal Co., Ltd.Urawa-shi, Saitama-kenJapan
  2. 2.Meiji UniversityKawasaki-shi, Kanagawa-ken214-8571Japan

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