Abstract: A method for checking the functionality of the voltage monitoring of a circuit is presented and described. The method includes a computing unit sending a test signal to a voltage source, which causes a change in the voltage of the voltage source. A comparison unit compares the voltage at the output of the voltage source with a reference voltage and sends a shutdown signal to a switch if the voltage at the output of the voltage source is outside a predetermined tolerance range. The switch interrupts the flow of current when it receives a shutdown signal, causing the voltage after the switch to drop. According to the invention, the computing unit measures the voltage after the switch and draws conclusions about the functionality of the voltage monitor based on this voltage.

Abstract: A device and a method for detecting an actuator by sonicating the actuator with sound waves through a sensor. The device is used in particular in a safety application. The sensor and actuator can be moved relative to each other. The sensor includes a sound wave transmitter, a sound wave receiver and a computing unit. The sound wave transmitter is designed to send sound waves in the direction of the actuator. The sound wave receiver, in turn, is designed to pick up the sound waves reflected by the actuator and convert them into an analog signal. The computing unit converts the analog signal into a digital signal and detects the actuator by comparing it with a reference signal.

Abstract: A device includes a sensor and an actuator. The sensor has a receiving circuit with a sensor and a detector, as well as a computer connected to the detector. The sensor cooperates with the actuator to generate a first receiving circuit signal during a normal operation when a switching distance between the sensor and the actuator is undershot. The detector generates a first output signal as a function of the first receiving circuit signal, and to transmit transmits the first output signal to the computer. The receiving circuit includes a signal emulator and a switch-over element. The signal emulator generates a second receiving circuit signal during a test operation. The detector generates a second output signal as a function of the second receiving circuit signal and transmits the second output signal to the computer. The device can repeatedly switch between normal operation and test operation.

Abstract: A device includes a sensor and an actuator. The sensor has a receiving circuit with a sensor and a detector, as well as a computer connected to the detector. The sensor cooperates with the actuator to generate a first receiving circuit signal during a normal operation when a switching distance between the sensor and the actuator is undershot. The detector generates a first output signal as a function of the first receiving circuit signal, and to transmit transmits the first output signal to the computer. The receiving circuit includes a signal emulator and a switch-over element. The signal emulator generates a second receiving circuit signal during a test operation. The detector generates a second output signal as a function of the second receiving circuit signal and transmits the second output signal to the computer. The device can repeatedly switch between normal operation and test operation.

Abstract: A method for the serial transmission of data from a sensor to a safety control device. The sensor has two data processing units which examine and process both the data of the sensor and the request data of the safety control device. The same request data of the safety control device are simultaneously supplied to each data processing unit and the data processing units simultaneously perform a check of the request data after receiving the data. The data processing units operate independently of each other. A sensor unit has a sensor, a safety control device and data processing units. The safety control device is connected to the data processing units via a common serial bus and the data processing units are independent of one another and simultaneously perform the data processing. A system for securing hazardous areas of production facilities with a sensor unit.