2 research outputs found
A Tool for the Certification of PLCs based on a Coq Semantics for Sequential Function Charts
In this report we describe a tool framework for certifying properties of
PLCs: CERTPLC. CERTPLC can handle PLC descriptions provided in the Sequential
Function Chart (SFC) language of the IEC 61131-3 standard. It provides routines
to certify properties of systems by delivering an independently checkable
formal system description and proof (called certificate) for the desired
properties. We focus on properties that can be described as inductive
invariants. System descriptions and certificates are generated and handled
using the COQ proof assistant. Our tool framework is used to provide supporting
evidence for the safety of embedded systems in the industrial automation domain
to third-party authorities. In this document we describe the tool framework:
usage scenarios, the archi-tecture, semantics of PLCs and their realization in
COQ, proof generation and the construction of certificates
Towards a Property Preserving Transformation from IEC 61131-3 to BIP
We report on a transformation from Sequential Function Charts of the IEC
61131-3 standard to BIP. Our presentation features a description of formal
syntax and semantics representation of the involved languages and
transformation rules. Furthermore, we present a formalism for describing
invariants of IEC 61131-3 systems and establish a notion of invariant
preservation between the two languages. For a subset of our transformation
rules we sketch a proof showing invariant preservation during the
transformation of IEC 61131-3 to BIP and vice versa