Device with displaceable device part, in particular coordinate measuring device or machine tool

A device selected from the group consisting of coordinate measuring devices and machine tools, the device comprising:

• a displaceable device part;
• a drive for driving said displaceable device part and thereby effecting a displacement of said displaceable device part;
• a control unit connected to said drive and controlling said drive;
• a first signal transmitter for determining at least one of a position or a speed of said displaceable device part,
• a direct connection connecting said first signal transmitter directly to said control unit or an indirect connection connecting said first signal transmitter indirectly via a first signal evaluation device to said control unit so that, during an operation of the device, said control unit receiving information from said first signal transmitter relating to the at least one of the position or the speed of said displaceable device part and controlling said drive depending on the information received;
• a second signal transmitter for at least one of checking or redundantly determining the at least one of the position or the speed of said displaceable device part;
• a monitoring component configured to recognize at least one of an error of the device or a disruption to the operation of the device, taking account of signals of at least one of said second signal transmitter or information derived from said signals;
• a displaceable element;
• said second signal transmitter containing a signal transmitter unit having a radiation source, a matrix of radiation-sensitive detector elements and a signal processor for processing detector signals of said radiation-sensitive detector elements, said radiation source configured to radiate radiation onto said displaceable element displaceable in relation to said signal transmitter unit so that said matrix generates the detector signals depending on a relative position of said signal transmitter unit and said displaceable element;
• and
• said monitoring component connected directly or indirectly via at least one further component of the device to said signal processor.