Conveyor system
This simple application is for a conveyor (moving material machine) and how we implement it using ladder diagram and instruction list.

System requirements:

1. A plc is used to start and stop the motors of a segmented conveyor belt, this allows only belt sections carrying a copper plate to move.
2. The system have three segmented conveyor belts, each segment runs by a motor.
3. A proximity switch located at the end of each segment to detect the position of the plate.
4. The first conveyor segment  is always on.
5. The second conveyor segment turns on when the proximity switch in the first segment detects the plate.
6. when the proximity switch at the second conveyor detects the plate, the third segment conveyor turns ON.
7. the second conveyor is stopped, when the plate is out of detection range of the second proximity switch, after 20 seconds.
8. the third conveyor is stopped after 20 seconds, when the proximity swtch located at the segment doesn’t detect the plate.