Abstract: An encoder comprises position detecting device for detecting a magnetic pole position and a rotational position of a motor. The encoder also includes a memory portion for storing parameter information particular to the motor or the position detecting device. A transmitting portion of the encoder is provided for externally transmitting parameter information particular to the position detecting device as a differential signal. A transmission suspension request detecting device is provided for detecting that the differential signal is driven by a given signal externally provided such that the differential signal does not exist as a transmission signal and for generating a transmission suspension request signal requesting suspension of transmission of the differential signal.

Abstract: An arrangement is provided for determining the position of an object of measurement without contacting the object. The arrangement includes a sensor element that reacts to magnetic forces, and along which the object can be displaced. The sensor element is provided with at least one release element, which has two magnets that are fixed relative to one anther, are spaced from one anther, and are disposed in a vicinity adjacent to the sensor element. One of the magnets, in order to produce a unilaterally enlarged virtual air gap, is rotated by a given angle relative to the other magnet.

Abstract: A device for measuring the displacement of stems of valves having a spindle coupled to a stem of a valve and provided with two inductive pickups; each inductive pickup is formed by a fixed part and a movable part constituting a variable inductor, which, following a displacement of the stem and a rotation of the spindle coupled thereto, generates an inductance variation of the electric circuit associated thereto; electronic excitation and detection means are adapted to convert the inductance variations into a pair of digital signals whose difference is indicative of the displacement of the stem.