A device includes a logic circuit having first, second, and third input ports, a first output port, and a feedback path between the first output port and the third input port. In a first operating state, a logic state change at the first input port triggers a logic state change at the first output port, but a logic state change at the third input port does not trigger a logic state change at the first output port. This allows signals to be routed through the device. In a second operating state, a logic state change of the third input port triggers a logic state change of the first output port. This change is fed back, delayed by a time value, to the third input to maintain an oscillation with at least two edges. The frequency of this oscillation is used to determine a value of a measurement variable.