H series LCD multi-function harmonic meters can measure various common electric parameters such as active/ reactive, harmonic distortion, with functions of digital communication, over-range alarm, switch monitoring status, energy pulse output and analogue transmitting. H series are of high performance-cost ratio,can replace the conventional measuring indicators, power metering device, harmonic measuring meter. As an advanced smart and digital front end data sampling unit, the meters can be used in various control system, energy management system, substation automation,residential power monitoring, industrial automation, smart buildings, smart distributor,and switch gears. They are easy to install, connect, maintain. They need less project cost and field programming on spot for power grid grouping with different PLC and industrial control PC communication software.