... three-phase voltage,three-phase current,active power,reactive power,apparent power,frequency,power factor and 4-quadrant energy etc;It ... network:3-phase3-wire,3-phase4-wireAccuracy of measurement:voltage,current,active power.reactive power,apparent power:±0.5%Frequency:±0.1Hz Power ... :RS485 serialcommunication,applying MODBUS_RTU communication protocol SFDBE multifunctional network power instrument