Patent ID: 8620619

Claim:
A method for checking the operability of a rotary encoder, the method comprising the steps of: providing a rotary encoder with a sensor unit and with a monitoring unit; operating the rotary encoder including making measurements with the sensor unit to provide a pair of measuring signals, the pair of measuring signals being shifted in phase relative to one another and being representative of an amount of rotation or an angular position sensed by the sensor unit; with the monitoring unit, comparing the pair of measuring signals with reference information stored in the rotary encoder; with the monitoring unit, combining amplitude values of the pair of measuring signals to form a characteristic value; providing an association of characteristic values or characteristic value ranges with reference information, and storing the association in the rotary encoder as quality values which are representative of admissible amplitude value combinations; with the monitoring unit, selecting a quality value for the formed characteristic value based on the stored association of characteristic values and reference information; and with the monitoring unit, generating a monitoring signal with a signal content in dependence upon the selected quality value and representative of the operability of the rotary encoder.