PLC Based Part Sorting by Size Ladder Program

Ladder Programming example

To distribute each part to its proper destination according to its size

PLC Based Part Sorting based on Size

Control Specifications

The following operation should be performed in this unit.
Study the required specifications and then create the program and confirm the operation.

1) When [SW1] (X24) on the operation panel is turned ON, the conveyors move forward. When [SW1] (X24) is turned OFF, the conveyors stop.

2) When [PB1] (X20) on the operation panel is pressed, Supply command (Y0) for the robot is turned ON. Supply command (Y0) is turned OFF when the robot has moved from the starting point.(The robot will complete the part loading cycle.)

3) The robot supplies large, medium or small parts.

4) Large parts are led to the rear conveyor and small parts are led to the front conveyor. The part size is detected by the input Upper (X1), Middle (X2) and Lower (X3) on the conveyor.

PLC Input and Output List

Input	Type	Comment
X0	Starting Point	ON when robot is at Starting Point
X1	Upper	ON when part is detected.
X2	Middle	ON when part is detected.
X3	Lower	ON when part is detected.
X4	Sensor	ON when part is detected at right end.
X5	Sensor	ON when part is detected at right end.
X20	Part Supply Pushbutton	If Pushed One part Supplied on Conveyor
X24	Toggle Switch	Turns on Conveyor

Output	Type	Comment
Y0	Supply Part Command	One Part is supplied when Y0 is ON. A process cycle begins: Metal Cylinder repeats in order L
Y1	Conveyor Forward	Conveyor moves forward when Y1 is ON.
Y2	Conveyor Forward	Conveyor moves forward when Y1 is ON
Y5	Sorting Wing	Moves toward front when Y5 is ON.

Ladder Program Description:

Part size	Upper (X1)	Medium (X2)	Lower (X3)
Large	ON	ON	ON
Medium	-	-	-
Small	OFF	OFF	ON

In this exercise, the size of parts carried on the conveyor is to be sorted using three sensors shown on the above table.

· In order to sort parts according to the size, the size detection data should be stored. Each part is distributed to the proper conveyor according to its size turning Sorting wing (Y5) ON or OFF.

· When Y5 is set ON, a part is carried to the rear conveyor and when the Y5 is set OFF a part is delivered to the front conveyor.

Control the ON/OFF status according to the part size.

Ladder Program: