PLC Mitsubishi fx-Series STAR DELTA : 2 Timer for Safety. When you Change form STAR to DELTA. Sequence Control : Manual : Start Motor Step M1 on - M2 on - M3 on by Button Start/Stop Automatic : Start Motor Step M1 on - M2 on - M3 on by Timer Automatic : Start Motor Step M1 on - M2 on(M1 off) - M3 on(M2 off) by Timer