Translating Grafcet specifications into Mealy machines for conformance test purposes

Conformance test is a black-box test technique aiming at checking whether an implementation conforms to its specification. Numerous results have been already obtained in this field for specifications expressed in a formal language. However, these results cannot be applied for conformance test of industrial logic controllers whose specifications are given in standardized specification languages. To contribute to solve this issue, this paper proposes a method to obtain, from a Grafcet specification, an equivalent Mealy machine, without semantics loss. This method permits to describe explicitly and formally all the states and transitions that are implicitly represented in a Grafcet model.

Research Highlights
► A formal definition of IEC 60848 Grafcet specification language is proposed.
► Any non-timed Grafcet specification can be translated into a Mealy machine.
► A test sequence for conformance test can be built automatically from a Grafcet.