Synthesis Tool for Automation Controller Supervision

Abstract

The supervisory control theory is a conceptual framework to keep a discrete-event system in a desired state space by disabling controllable events. This paper introduces a new software tool to create supervisors for actual, physical plants in terms of a PLC code implementation. It points out the differences between SCT-synthesized supervisors and controllers and identifies a scenario in which practical applications can benefit from supervision. The presented tool provides a graphical user interface for the modeling and a template-based code generator. For safety specifications, a slightly altered automaton principle, called restricting specification, is used with the goal to decrease the manual modeling effort. Furthermore, event preemption is supported, which allows to permissively supervise controllers that react to uncontrollable events. This paper intends to give a brief overview of the key features of the tool.