3 Basic Instructions Program Example: Ladder diagram: Instruction code: Operation: EI Allowable range for interruption EI Enabling interruption X1 OUT Y1 Driving Y1 coil LD X1 Loading A contact of X1 Y1 : Pointer of interruption program DI DI Disabling interruption FEND : Y2 X2 FEND Main program ends I 001 Interruption subroutine LD X2 Loading in A contact of X2 IRET OUT Y2 Driving Y2 coil : IRET Interruption return DVP-PLC Application Manual 3-18 I001 Interruption pointer