Programmierregeln fuer die Erstellung von Software fuer Steuerungen mit Sicherheitsaufgaben

Abstract

The paper is an investigation into programming languages and their influence on safety technology. The general part of the presentation is devoted to typical software failures and their classification based on incidents and accidents due to faulty software. Such failures can be avoided by a bundle of preventive measures among with the 'Programming guidelines' shall be particularly highlighted in this paper. A number of well-known methods are referred to as being the basis for any programming guideline: the structured and modular programme design, the top-down/botton-up design and the object-geared design. A general chapter introduces core principles for software design and coding. These principles apply to any known programming language, including Assembler and the SPC languages. Special chapters deal with the following programming languages: BASIC, PASCAL, MODULA-2, ADA, C, C"+"+, FORTRAN and Assembler. Each chapter includes a description of the most important concepts and constructs of the language, its advantages and shortcomings and the coding guidelines. The latter distinguish: data-specific aspects, arithmetic calculations, modules and functions, information relating to the control flow and recommendations for the elaboration and documentation of the source text. Reasons are given for all of the guidelines, and examples are provided to illustrate them. Language-related tables give an overview of the totality of guidelines and indicate the safety-integrity-level (according to IEC 61508) and also the category (according to EN 954-1) to which they apply. The programming rules try to define the language subsets for safety-related software in a pragmatical way. (orig.)Available from TIB Hannover: RA 3864(812) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman