A potentiometer device, for detecting valve positions, wherein a voltage signal U_s is sendable to a control unit having an A/D converter, including a carrier element on which at least one slider track, having a slider element in contact therewith, is disposed; wherein the slider track switches between supply voltage U_v of the control unit and ground, and the slider element is connected with the control unit with a protection resistance over an output, wherein the control unit includes a resistance for detecting a cable disconnect, which is a pull-down resistance between voltage signal U_s and ground, or a pull-up resistance between supply voltage U_v and voltage signal U_s, wherein a resistance is provided at output, that is, in a first embodiment, a pull-up resistance between supply voltage U_v and voltage signal U_s, and, in a second embodiment, a pull-down resistance between voltage signal U_s and ground.