A reliable and efficient electric distribution network depends on a real-time acquisition system and data transmission. Monitoring the dynamic performance of large areas of the transmission systems is based on Phasor Measurement Units (PMUs). The advantage of using PMUs is a high data acquisition rate and the synchronization of measurements using Global Positioning System (GPS). This paper presents the development of a low-cost PMU prototype, based on IEEE C37.118 standards, using Digital Signal Processor (DSP).