Digital Twins of the Manufacturing System Based on a Simulation Model with Bi-directional Process Data Exchange

Effective implementation of the Industry 4.0 concept requires searching for effective methods of creating digital twins - digital models connected and able to communicate in real-time, directly with mapped real objects. These methods must also take into account the need to obtain reliable and up-to-date data from the facilities of the generation system and its individual elements. The paper presents an architecture proposal for a solution of a cyber-physical system integrating the discrete events simulation model with the control system, An example of the practical implementation of the concept of a digital twin of a production system based on a dynamic digital simulation model is shown. Thanks to the possibility of mapping the current state of the production system object through a data access platform that collects, analyzes, processes and stores process data and the digital model connected to it using communication protocols, it is possible to compare and analyze the behavior of a system with nominal parameters. Mechanisms of automatic updating of the state of objects through the model-production system interfaces were used, using the built-in so-called emulation tools of industrial automation components, ensuring support for the OPC UA, OPC DA and Modbus communication protocols.