Patent ID: 8525101

Claim:
Position transmitter for the acquisition of the position of a shaft ( 4 ) which is rotatable about an axis of rotation ( 3 ), comprising: a first optical sensor arrangement ( 12 ) for the acquisition of a single-turn position of the shaft, and a second optical sensor arrangement ( 13 ) for the acquisition, in particular for gearless acquisition, of a multi-turn position of the shaft. a first evaluation unit ( 14 ) for evaluating the single-turn position; a second evaluation unit ( 15 ) for evaluating the multi-turn position; and a control/evaluation unit ( 16 ), for processing the single-turn position and the multi-turn position, wherein the position transmitter has at least two operating modes comprising: a normal mode, the position transmitter operating in the normal mode when applying an external voltage supply from an external power supply and; a power-saving mode, the position transmitter operating in the power-saving mode when the external power supply is switched off or fails, wherein in the normal mode the multi-turn position is determined by both the first optical sensor arrangement and the second optical sensor arrangement and a comparison of the two determined positions is carried out.