Patent ID: 8135977

Claim:
Process for digital, bidirectional data transmission between a processing unit and a position encoder, as based on the transmission of frames of a predetermined bit length, such that each frame is provided with at least a first bit length for the transmission of data from the processing unit to the position encoder and at least a second bit length for the transmission of data from the position encoder to the processing unit, and such that the frame is provided with a time slot in which data is transmitted neither from the processing unit to the position encoder nor from the position encoder to the processing unit and in which a triggering signal (external sync signal) is transmitted from the processing unit to the position encoder and this signal triggers the acquisition of position data, wherein a clock signal for synchronizing the processing unit and the position encoder is transmitted within the first bit length from the processing unit to the position encoder, and following the acquisition of position data triggered by the external sync signal, the acquired position data is transmitted from the position encoder to the processing unit, and between the transmission of two successive external sync signals at least one additional position-request signal (internal sync signal) is transmitted from the processing unit to the position encoder, and this signal triggers another acquisition of position data, which is followed by the transmission of the acquired position data from the position encoder to the processing unit.