... LED to show the above value. 3 phase 3 lines or 3 phase 4 lines is OK4) Alarms: Up to 4 relay output for ... RS232 or RS485 communication, Modbus RTU protocol.7) With power down memory function for KWH / KvarH.8) Power supply: 18 ... (TC and RTD), Panel Meter, Sensor Meter, inductor, Power Meter, Coulometer, Voltage Meter, Ampere Meter, Counter, Tacho Meter, Frequency Meter, flowmeter,Timer,Timer Relay, ...