Self-tests for microprocessors incorporating safety functions or: "Quo vadis, fault?" (BGIA-Report 7/2006e)

Summary: The increasingly widespread use of microprocessors in safety-related products such as controls and sensors has led to particular requirements being placed upon their safety. The response of the controller in the event of a fault must be deterministic, and hazardous operations must be preventable. For such supplementary measures which are to be taken during the design of safe controls, this report describes processor tests by which the systems concerned are to be made suitably robust for safety-related applications. The measures presented here are software modules written in the Assembler programming language. Based upon the arrangements for error detection required by the standards, these measures enable the required level of safety to be attained in conjunction with the system architecture (structure) employed. The measures described represent snapshots of possible solutions, and should be regarded as examples only.

Reference to the use of the software:

Users use the software at their own risk. To the extent permissible by law, no liability will be accepted for the software on any legal basis. In particular, no liability will be accepted for material defects or defects in title, whether in the software or in the associated documentation and information, particularly with regard to their correctness, freedom from errors, freedom from property rights and copyright of third parties, up-to-dateness, completeness and/or fitness for purpose, except in cases of malicious or wrongful intent.

The BGIA - Institute for Occupational Safety and Health of the German Social Accident Insurance undertakes to keep its website free of viruses; nevertheless, no guarantee can be given that the software and information provided are virus-free. Users are therefore advised to take appropriate precautions of their own and to use a virus scanner before downloading software, documentation or information.