Write the PLC programming for a continues box filling operation that requires boxes moving on a conveyor to be automatically positioned and filled.
Automatic Box Filling System
Develop ladder logic program according to the logic given below,
- Energize the RUN status light when the process is operating.
- Energize the STANDBY status light when the process is stopped.
- Stop the conveyor and energize the standby light when the right edge of the box is first sensed by the photo sensor.
- With the box in position and the conveyor stopped, after 3 seconds open the solenoid valve and allow the box to fill.
- The filling should stop when the level sensor goes true.
- Energize the FULL light when the box is full. The FULL light should remain energized until the box is moved clear of the photo sensor.
Box Filling using PLC Logic
Start/Stop PB latched with memory B3:0/0.
B3:0/0 enabled to turn on Run status light (O:0/0) and Conveyer motor (O:0/1).
The Photosensor is connected in normally closed contact to turn off the outputs when the box reaching photo sensor.
Standby status light (O:0/1) should turn ON when the Process is in stop condition.
So Start latch and run status light output are connected in normally closed contact.
When the box reaching the photo sensor, the conveyer gets stopped and after 3 seconds interval solenoid valve (O:0/3) is turning ON until level sensor (I:0/3) ON which is connected in normally closed condition.
When the Level sensor (I: 0/3) is in ON condition, Full status light output (O:0/4) will ON until the photo sensor goes off (until the box is moved clear off).
Author: Hema Sundaresan
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