Concepts for Real-Time Execution in Safety-Critical Applications
Abstract
Programmable electronic systems (PESs) that are currently employed in safety-critical applications follow either a strictly periodical or a task-based operating policy. This paper discusses these policies with regard to safety aspects and introduces a novel real-time execution concept that combines their advantages. The main characteristics of this new concept are quantisation of time into discrete execution intervals, and partitioning of tasks into execution blocks matching these intervals. This operating principle features task-based software execution without utilising interrupts, eases integration into a holistic safety concept, and conforms particularly well with the safety standard IEC 61508.
