Ladder Programming example To distribute each part to its proper destination according to its size
PLC Based Part Sorting by Size Ladder Program
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.
