Integration of control loops in an UML based engineering environment for PLC

This paper presents a UML-based engineering environment for the design and implementation of hybrid systems in forming technology. The discrete superordinate steps of forming technology are programmed as an activity diagram (UML). Some process steps include control loops which are modeled in Simulink. The control loops are automatically generated into Continuous Function Chart (CFC) in Programmable Logic Controller (PLC). The paper describes how the controllers can be distributed with different task cycle times and how the performance of these controllers can be ensured during runtime. In the process, the activity diagram is compared with the standard IEC 61499 considering the aspects usability and execution/implementation.