The meter can have infrared communication interface and RS-485 communication interface, and supports Modbus-RTU protocol and DLT645-97 (07) protocol at the same time. The meter can have relay alarm output and digital input function; You can set the ratio, alarm, and communication through the meter panel keys according to different requirements. The meter can have event recording of switch (Modbus protocol), programming and event setting records (645 protocol), instantaneous and timing freeze function of data (645 protocol), maximum and minimum value recording function of voltage and current power.