Is it possible to switch off any function displaying/LED-flashing of the MOUSE-E-MOTION Universal Data Logger?

Yes. The data logger can be configured (through the MOUSE-E-MOTION Excel add-in) to not emit any light (LED-) signals during logging operation. However, no distinction between the operational modes “powered off” and “logging” is possible any longer then. Hence, it is impossible to control if the device is properly operating in this case.