PLC Ladder Program Example : How to Detect the size of each part and distribute it to the specified place.
Control Objective:
Detect the size of each part and distribute it to the specified place.
PLC Ladder Program Example for Detect the size of each part and distribute it to the specified place
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 [PB1] (X20) on the operation panel is pressed, Supply command (Y0) for the hopper is turned ON. When [PB1] (X20) is released, Supply command (Y0) is turned OFF. When Supply command (Y0) is turned ON, the robot supplies a part.
2) When [SW1] (X24) on the operation panel is turned ON, the conveyors move forward. When [SW1] (X24) is turned OFF, the conveyors stop.
3) Large, medium and small parts on the conveyors are sorted by the input of sensors Upper (X0), Middle (X1) and Lower (X2) and carried to the specified trays.
• Large part
:
Pushed to the lower conveyor and carried to the right tray.
• Medium part
:
Moved to the tray by the robot.
• Small part
:
Pushed to the lower conveyor and carried to the left tray.
4) When
the sensor Detect part (X3) is turned ON, the conveyor stops and a large
or small part is pushed to the lower conveyor.
Note:
When
the actuating command for the pusher is set ON, it extends completely.
When the actuating command is set OFF, the pusher retracts completely.
5) When Part on table (X5) is turned ON in the robot, Unload command (Y4) is set ON. When Robot operation finished (X6) is turned ON (it is ON when a part is placed on the tray), Unload command (Y4) is set OFF.
6) While [SW2] (X25) on the operation panel is ON, a new
part is to be automatically supplied at the following time.
•
When the robot
starts to carry a medium part
•
When a small
or large part is put into a tray
PLC Ladder Program Description:
In this exercise, the
size of parts carried on the conveyor is to be sorted using three sensors shown
on the table.
Part size
Upper (X0)
Medium (X1)
Lower (X2)
Large
ON
ON
ON
Medium
OFF
ON
ON
Small
OFF
OFF
ON
The
programs for this exercise can be classified into the following controls.
1)
Program
to supply the part from the hopper
2)
Program
to detect part size and store the data
3)
Program
to operate the conveyors
4)
Program
to detect a part to be pushed to the lower conveyor and to stop the conveyor
5)
Program
to push a part to the lower conveyor
6)
Program
to carry a medium part to the robot and to move it to the tray
7)
Program
to move the lower conveyor forward or backward according to the detected part
size
8)
Program to reset the
part size data after the specified processes have finished and to supply the
next part depending on the switch condition
Turn ON [SW1] (X24) on the operation panel.
Result>>The conveyor moves to the right
Press [PB1] (X20) on the operation panel.
Result>>A part is supplied from the hopper
Sorting part size
• Large part
:
Pushed to the lower
conveyor and put on the right tray.
• Medium part
:
Moved into the tray
by the robot on the upper conveyor.
• Small part
:
Pushed to the lower
conveyor and put on the left tray.
Operation while [SW2] (X25) on the operation panel is ON
Result >>The
next part is supplied from the hopper when the robot starts to move a medium
part or when a small or large part is put on a tray.
