Hello there,
i am a new to the side of automation and i was tasked to create a program using m221 and ladder language to control 3 pumps automatically using permutation, could anyone please help guide me or do u have any existing programs i can see so i could learn from them

 

What is the permutation meant to do, control the starting order of pumps or something else?
Are individual pumps started/stopped due to demand or something else?

 

well basically there should be 3 pumps 2 of them have to be on while the other one rests. we choose which one should be on based on the number of starts the pump had. and if a pump has failure of any kind the other pump should cover for it.

 

I have done something similar but based on the run hours of the motors instead of the number of starts. As you only want one motor off this will simplify your logic, you just need to work out which motor has the highest number of starts and make sure the other two do not have any failures. My code is in Structured Text but it would be easy enough to do in ladder as well.