... Sum:1mAPhase SequencePositive Phase Sequence:U1,U2,U3 or I1,I2,I3 cursors blink in order from left to rightNegative Phase ... Sequence:U1,U2,U3 or I1,I2,I3 cursors blink in order from right to leftSampl e ... ; Guarantee Card : 1 pc; Certification: 1 pc. .Field Application ETCR4300 Intelligent Three Phase Digital Phase Volt-Ampere Meter----Manufactory, RS232 interface