A control signal protection device protects a current-receiving field device from an undesirable interruption in a control signal provided to the field device. The control signal protection device includes a first terminal to connect the signal protection device to a control system and a second terminal that connects the control signal protection device to a field device. The control signal device further includes a power storing element for temporary accumulation of electric energy and a switching circuit for controlling operational mode of the signal protection device. Electric energy is stored in the power storing element in a first operational mode. Electric energy stored in the power storing element is supplied to a positive terminal in the second terminal pair in a second operational mode.