Net condition/event systems with multiple condition outputs

The modeling of production systems of realistic size requires modeling techniques which have the capability to build large models from smaller ones. The authors assume that these small models which describe simple elements of the plant are finite state machines or Petri nets. The authors call these simple submodels modules. If the authors want to synthesize larger models from the modules, they describe the interactions of the modules by signals. Modules can interact by event signals which force state transitions in the module receiving the event signals (the supervisor) and by condition signals. Based on this idea, the uniform, modular modeling concept of condition/event systems (C/E systems) has been introduced by Sreenivas and Krogh (1991). The definition of C/E systems as input-output systems with two types of signals does not imply a particular form of the models to represent the dynamic behavior of the modules. The authors present an approach to studying the behaviour of modules which is inspired by the work by Sreenivas and Krogh on Petri net representation of condition/event systems