Siemens PLC Programming with Example
With 4 separate buttons, 4 separate motors can be activated and the engine or engines operating with a stop button are stopped. No motor stays on for more than 30 minutes,
If any motor has been on for 30 minutes, a red light will come on and that motor will stop immediately.
Engagement times of the engines are important. Because, even if the start is pressed after the stop button is pressed, every motor cannot be activated until the period that it remains active.

