PC with simulation of the controlled system in WINMOD is connected to a PC with software PLC by Profibus. Communication between a PC with software PLC and a PC with visualization in WINCC is done through Industrial Ethernet. Software PLC SIMATIC WinAC RTX 2005 is suitable for control applications which require efficient control system, large data transfer, data processing and quick response in real time. WinAC RTX 2005 works on a standard PC with operating systems Windows XP Professional or Windows XP Embedded. This configuration is named soft real time systems, because of non-deterministic operating systems with special kernel packages installed with WinAC RTX 2005 software.