A safe programmable electronic system

A dual-channel computer architecture for utilisation in programmable logic controllers is presented. Faults can be detected by novel high-speed comparators with fail-safe operation. The cyclic operating mode of PLCs and a specification-level, graphical programming paradigm based on the interconnection of application-oriented standard software function modules are architecturally supported. Thus, by design, there is no semantic gap between the programming and machine execution levels enabling the safety licensing of application software by an extremely simple, but rigorous method, viz., diverse back translation.