Digital signal processing, together with a strong integration of protection, metering, control and communication functions led to the use of a high performance hardware platform: there is a 32-bit CPU and a DSP (Digital Signal Processor) for processing the measurement algorithms. Flash memories, together with the local communication interface, enables the firmware to be updated quickly and reliably. The measurement and digital filtering of the signals enables the relays to perform the main protective functions with extreme accuracy and repeatability.