1856B05 has been adopted electromagnetic isolation principle, high speed DSP and professional MCU controller for isolate and measurement of full electric quantities from three phase system. Measured electric parameters are three phase voltage (RMS), three phase current (RMS), active energy (signed) active/reactive power (signed), apparent power, power factor (signed), frequency, 1-19 times harmonic voltage/ current component, positive, negative and zero sequence voltage/current etc. the output is RS485 communication port. The product has certain advantages of total galvanic isolation between input/output and auxiliary power, high accuracy, compact and small, low drifting by temperature, and wide temperature bearable range, and cost effective.  The product is used for the protection system of electric motor, electric power supply and distribution system.