... 4 digit LED to show the above value. For DW9E model, additional 1 line 8 digit to ... 5) True effective value measuring;6) Two alarm output for voltage, current, power factor, active power, reactive power ... ;7) Transformed analog output 4-20mA for voltage, current, active power, reactive power, frequency, power ... Modbus RTU protocol);9) With power down memory function for KWH / KvarH.