The present invention generally relates to proximity sensor monitors and proximity monitor systems incorporating proximity sensor monitors. A proximity sensor monitor measures the impedance or other electrical characteristics of a proximity sensor component to determine the presence of a target. The proximity sensor monitor performs this measurement independently of a separate proximity sensor. The proximity sensor monitor is configured to compensate for differences between the measurement frequency of the proximity sensor monitor and the driving frequency of the proximity sensor.

A sensor element of an inductive proximity sensor or distance sensor contains a coil arrangement with at least one excitation coil and at least one receiving coil and includes an electrically conductive shielding which contains a shielding cup that surrounds the coil arrangement laterally and on the rear face. A method operates the sensor element. The shielding of the sensor element further contains a flange which is provided on the front face of the sensor element, is connected to the shielding cup in an electrically conductive manner, and completely surrounds the coil arrangement.

A system may include a sensor having a variable phase response, a dummy impedance having a known phase response, and a measurement circuit communicatively coupled to the sensor and configured to measure first phase information associated with the sensor, measure second phase information associated with the dummy impedance, and determine a phase response of the measurement circuit based on a comparison of the first phase information to the second phase information.

A safety switch with detection of the end-stroke of the unlocking mechanism adapted to supervise a safety access of a machine or industrial plant comprises a switching device (2) adapted to be associated to the fixed part of an access to be supervised and having switching means (5) adapted to be operatively connected to one or more control and/or service circuits of the plant for the control thereof, an operating device (3) associated to a movable part of the access to interact with the switching means (5) at the time of opening/closing of the access for opening/closing of one or more circuits, an unlocking mechanism (13) housed in the switching device (2) and having an unlocking pin (14) adapted to translate with maximum predetermined stroke from a blocking position of the access to an unlocked position to determine the opening of the switching means (5), means (17) for the detection of the stroke of the unlocking pin (14) comprising a first detector (18) adapted to detect the start of the stroke of the unlocking pin (14) and a second detector (19) adapted to detect the end of the stroke of the unlocking pin (14).

Self-testing proximity testing systems and corresponding methods are discussed herein and can include a proximity probe and controller in electrical communication via a cable. A self-testing subsystem can be in communication with the controller and configured to determine whether proximity probes and cables assembled with a controller are compatible or incompatible. The self-testing subsystem can place a known impedance in electrical communication with the controller, modifying a proximity signal output by the controller. When the modified proximity signal differs from a predicted proximity signal by greater than or equal to a threshold amount, the self-testing subsystem can output a first indication indicating that incompatible proximity probes and cables are assembled with a controller. When the modified proximity signal differs from a predicted proximity signal by less than the threshold amount, the self-testing subsystem can output a second indication indicating that compatible proximity probes and cables are assembled with a controller.

A method of measuring target proximity comprising the steps of transmitting a magnetic field signal by a controller of a proximity sensor at a target, measuring impedance of an inductor of a proximity sensor, calculating a relative position of the target in relation to a sensor face, and providing a near/far output status of the target at a predetermined rate.

A system for sensing a position of a locking bolt of an industrial locking switch includes an inductive circuit, a converter, and a master controller. The inductive circuit includes an inductive coil and a capacitor electrically connected in parallel. The inductive coil is positioned to receive a locking bolt of an industrial locking switch when the locking bolt is transitioned to a lock position. The converter is configured to convert a frequency of a current signal on the inductive circuit to a digital frequency value. The master controller is configured to generate a bolt detection signal in response to determining that the digital frequency value changes by an amount equal to or substantially equal to a defined frequency shift corresponding to a frequency shift induced by the inductive coil in response to presence of the locking bolt within the inductive coil's magnetic field.

A system may include a sensor configured to output a sensor signal indicative of a distance between the sensor and a mechanical member associated with the sensor, a measurement circuit communicatively coupled to the sensor and configured to determine a physical force interaction with the mechanical member based on the sensor signal, and a compensator configured to monitor the sensor signal and to apply a compensation factor to the sensor signal to compensate for changes to properties of the sensor based on at least one of changes in a distance between the sensor and the mechanical member and changes in a temperature associated with the sensor.

A system may include a sensor configured to output a sensor signal indicative of a distance between the sensor and a mechanical member associated with the sensor, a measurement circuit communicatively coupled to the sensor and configured to determine a physical force interaction with the mechanical member based on the sensor signal, and a compensator configured to monitor the sensor signal and to apply a compensation factor to the sensor signal to compensate for changes to properties of the sensor based on at least one of changes in a distance between the sensor and the mechanical member and changes in a temperature associated with the sensor.

A proximity switch is disclosed. In an embodiment, the proximity switch has a defined detection range and includes an oscillator, an oscillator amplifier, a temperature sensor, a microprocessor and a storage medium. The oscillator generates an alternating magnetic field and changes its oscillation state as a result of a target entering the detection range. The oscillator amplifier is configured to be controllable in an open-loop and closed-loop manner and has at least one amplifier stage. In this embodiment, the at least one amplifier stage has a controllable temperature compensation circuit which is configured to influence the oscillation behaviour of the oscillator based on compensation values received as control data from the microprocessor and/or from the storage medium, depending on a temperature detected by the temperature sensor. The disclosed embodiments also encompass a method for operating a proximity switch with temperature compensation.