Control system (1, 4), comprising - a real controller for controlling an industrial process, an installation or a machine, - a virtual controller for simulating the control of the industrial process, the installation or the machine, - synchronization means for synchronizing the real controller and the virtual controller, - a control monitoring device for capturing data of the real controller and the virtual controller, - wherein the control monitoring device is designed to compare the data captured or originating from the real controller with the data captured or originating from the virtual controller, characterized in that - unexpected operating states of the real controller are identifiable from the comparison, wherein time-based data and/or state-based data are transferable from the real controller to the virtual controller for the purpose of synchronizing the virtual controller to the real controller, - wherein the control monitoring device is able to analyse an identified unexpected operating state of the real controller by means of the comparison of the data captured or originating from the real controller with the data captured or originating from the virtual controller, and is able to take an analysis result as a basis for performing a specific predefined or predefinable reaction, - wherein the control monitoring device is designed to react differently to different analysis results, wherein if the analysis leads to the result that there is just a slight divergence between the real system and the virtual system, a moderate reaction by the control monitoring device to this unexpected operating state is effected by means of output of an error message, and wherein if, on the basis of the data analysis, it is not possible to discover a precise reason for the divergence of the virtual system from the real system and the divergence is serious, the control monitoring device is designed to react to the unexpected operating state by shutting down the relevant machine and reporting to a superordinate control system accordingly. - a real controller for controlling an industrial process, an installation or a machine, - a virtual controller for simulating the control of the industrial process, the installation or the machine, - synchronization means for synchronizing the real controller and the virtual controller, - a control monitoring device for capturing data of the real controller and the virtual controller, - wherein the control monitoring device is designed to compare the data captured or originating from the real controller with the data captured or originating from the virtual controller, characterized in that - unexpected operating states of the real controller are identifiable from the comparison, wherein time-based data and/or state-based data are transferable from the real controller to the virtual controller for the purpose of synchronizing the virtual controller to the real controller, - wherein the control monitoring device is able to analyse an identified unexpected operating state of the real controller by means of the comparison of the data captured or originating from the real controller with the data captured or originating from the virtual controller, and is able to take an analysis result as a basis for performing a specific predefined or predefinable reaction, - wherein the control monitoring device is designed to react differently to different analysis results, wherein if the analysis leads to the result that there is just a slight divergence between the real system and the virtual system, a moderate reaction by the control monitoring device to this unexpected operating state is effected by means of output of an error message, and wherein if, on the basis of the data analysis, it is not possible to discover a precise reason for the divergence of the virtual system from the real system and the divergence is serious, the control monitoring device is designed to react to the unexpected operating state by shutting down the relevant machine and reporting to a superordinate control system accordingly.