Design and Deployment of Digital Twins for Programmable Logic Controllers in Existing Plants

: Digitization and network integration of production environments are two core prerequisites for changeable production environments according to a digital factory. In addition, consistent and cross-system descriptions of the equipment and abilities are required over the entire life cycle of plants. This descriptions can be done with Asset Administration Shells, which are a useful tool for the design of new facilities and their system components. Currently, industrial plants usually use programmable logic controllers, which are programmed with domain-specific programming languages. The use of these programming languages leads to an inflexible coupling of programmable logic controllers and their sensors and actuators with the process. If the plant configuration is changed later, a new engineering process with extensive reprogramming is required. However, in many cases, clarity and completeness of changes are not sufficiently addressed in the accompanying documentation. The paper discusses the results of the project ”OpenBasys 4.0”. A project goal is to retrofit a conventional existing plant with programmable logic controllers into a reconfigurable plant design by using the BaSys 4 middleware. A method was developed and exemplarily implemented on a prototype. The focus of the method is on the automated generation of Asset Administration Shells and their use.