What are the two methods commonly used to represent a timer within a PlC's ladder logic program? a. Explain the difference between the operation of a nonretentive timer and that of a retentive timer....

What are the two methods commonly used to represent a timer within a PlC's ladder logic

program?

a. Explain the difference between the operation of a nonretentive timer and that of a

retentive timer.

b. Explain how the accumulated (ount of programmed retentive and nonretentive timers is

reset to zero.