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Basic Process Control

pen vs Closed Loop
! Closed loop
! Automatic control
! Open Loop
! Manual control
! Person takes the place of the controller

A problem
Output initially 50%, Gain = 2, reset = 2 minutes per repeat
A direct acting controller control is subjected to a sustained
error of 5%
What is the output after 4 minutes?
Proportional Response = ke = 2x5=10%
Integral Action- in 4 minutes the control will go through 2 repeats.
Integral action = 2 x 10 = 20%
Total output change is proportional + integral = 30%