The TwinCAT 3 Usermode Runtime provides a way to run the applications programmed in TwinCAT without real-time properties in the user mode of the operating system. The TwinCAT?3 Usermode Runtime can be used free of license costs purely for engineering purposes and only requires (trial) licenses of the TwinCAT products used. The °∞Fast As Possible°± option ®C which is subject to license costs ®C provides an interface that runs the application as fast as the hardware allows. This also simulates different cores and clock speeds. An interface is available for the application to use the °∞Fast As Possible°± option accordingly and to be able to change it during the run. Calculated results of an application can be previewed with this option.