1. Basic Program Design Examples 1.6 Interlock Control Circuit Y1 Y0 X0 X1 Control Purpose: z The Entry/Exit of the parking lot is a single lane passage. By controlling the indicators, the program ensures that only one car can pass through the Entry/Exit so as to prevent car accident between entering and leaving cars Devices: Control Program X0 Y0 Y1 Entering Indicator X1 Y0 Leaving Indicator Y1 Program Description: z In the parking lot, there are two indicators individually directing the entering and leaving cars. By the interlock control circuit, only one indicator will show “GO” signal and the car accident will thus be prevented.
z When an entering car draws near the vehicle control barrier, X0 will be ON and so will Y0. The entering car indicator will show “GO”. At the same time, the leaving car indicator will z When a leaving car draws near the vehicle control barrier, X1 will be ON and so will Y1. The show “STOP.” Car entering is allowed but leaving is prohibited in this case. leaving car indicator will show “GO” and the entering car indicator will show “STOP.” DVP-PLC Application Examples 1-6 Device Function X0 Car entering sensor. When a car passes through the sensor, X0 = ON. X1 Car leaving sensor. When a car passes through the sensor, X1 = ON.
Y0 Entering car indicator（ON means “GO”, OFF means “STOP”） Y1 Leaving car indicator（ON means “GO”, OFF means “STOP”）