2. Benefits of the latest revision of the standard

For many years, specifiers have been faced with a number of difficulties related to :

• the growing number of inputs and outputs to be managed by control systems;

• complex sequential behavior requiring the definition of numerous operating states;

• highly-developed – machine interfaces;

• numerous operating and maintenance procedures (local and remote controls, production campaign changeovers, various recipes in continuous and batch processes, operating safety procedures, etc.);

• behavior combining combinatorial, sequential and continuous elements.

Users therefore called for a revision of the GRAFCET standard, to clarify certain notions and enrich this standardized specification...