Abstract: A position/displacement transducer apparatus includes encoders arranged along a measurement path along which a position/displacement encoding periodic array is arranged, having contiguous elements with alternate dual characteristics. There is at least one transition region of discontinuity in periodicity of the periodic array and/or unreadable, the periodic array subject to a mutual motion with respect to encoders along the measurement path, defining the ends of a reading window having a greater length than the estimated maximum size of the transition region so they are not simultaneously involved by the transition region during mutual motion. A controller emits a transduced position/displacement on the basis of signals from encoders and switches from use of one encoder to use of the other to manage the presence of the transition region. The controller switches from default use temporarily to use of the upstream encoder while the downstream encoder is at the transition region.