The SIMATIC WinAC RTX handles the actual control task and execution of the user program. It coordinates the necessary input and output of process values through the lower-level PROFINET fieldbus system and provides the process values for visualization and data processing tasks.

The distributed I/O connection is made via PROFINET, for which the integrated interface (2 ports, switched) of the EC31 is used. By using the IO modules of the S7-300 (SM modules), the IO can also be connected centrally and, if necessary, extended as in the case of the S7-300. If required, additional PC interfaces are available via the extension modules.