TPS-NU is a teleprotection device that allows to protect power lines in a flexible, reliable and economic way. The device can be equipped with digital or analog line interfaces. As for digital interfaces, the operating principle is based on the decoding of the guard signals and the sending of a certain number of commands decoded using specific bit sequences. With regard to analog interfaces, the TPS-NU device is based on FSK (Frequency Shift Keying) operation.