There are four normally open input sensors to an annunciator system that switches the output alarm ON if some operational malfunction occurs. Design a program that operates the alarm system as...

There are four normally open input sensors to an annunciator system that switches the output alarm ON if some operational malfunction occurs. Design a program that operates the alarm system as follows: If any one input is closed, nothing happens. If any two inputs are closed, a green pilot light goes on. If any three inputs are closed, a yellow pilot light goes on. If all four inputs are closed, a red pilot light goes on. Enter the program into the PLC, and prove its operation.