In a device and a method for transmitting energy and data between a control unit and a position-measuring device via a line pair, the energy transmission takes place in a charge mode and the data transmission takes place in a communication mode, and an energy storage device is provided in the position-measuring device, which is able to be charged in the charge mode via the line pair, and which is able to supply energy to the position-measuring device in the communication mode, and a charge unit and a switching device are provided in the control unit. The switching unit is adapted to the charge unit to the line pair in two-pole manner.