Technological implementation of GRAFCET

In order to implement the GRAFCET technology on different media (wired or programmed), a three-stage design is recommended:

• functional analysis, leading to the creation of a GRAFCET that is independent of the technological implementation;

• the transcription of the GRAFCET into logical equations that can be used in the technological realization ;

• the implementation of logic equations on the wired or programmed implementation medium.

This approach highlights the difficulties of functional design for complex applications, and proposes a solution through decomposition into less complex modules and dialogues between the GRAFCETs describing them.

As the functional part only takes into account the normal operating mode, the notion of on/off modes is integrated into the logic equations, and thus into the technological realization.

This article complements other articles on GRAFCET, including Outil de description des automatismes séquentiels : le GRAFCET [R 7 250].