The invention relates to a polling system for a moved machine component, comprising a polling subunit that is to be disposed at the machine component end and is provided with at least one switch which operates without power in a certain state of the machine component or a certain position of a part of the machine component, a radio transmitter unit that evaluates the switching modes of the switch and transmits the evaluated switching signals with digital radio switching signals, and an electric power source for supplying the radio transmitter unit. The inventive polling system further comprises a radio receiver unit which is stationary relative to the polling subunit and is used for receiving and evaluating, forwarding and/or displaying the signals received from the radio transmitter unit.