Technical data

Controller parameters
P controller The parameter for a P controller is K. This is the quotient of the
output and input value: K = X
out
/X
in
.
PI controller The parameters for a PI controller are the proportional cooefficient K
and the reset time TN. The proportional cooefficient K is the quotient
of the output and input value and determines the P action. The reset
time TN is the time required to respond to achieve the same change in
the manipulated variable due to the I action as occurs due to the P
action.
PD controller The parameters for a PD controller are the proportional cooefficient K
(see above) and the derivative time constant TV. The derivative time
constant is the time a P controller would require at a constant rate of
change of the input variable to bring about the same change in the
output variable that is brought about immediately by the D action of a
PD controller. To determine the derivative time constant, a linear
change in the input variable is assumed and not a jump function.
X
in
X
out
t=0 tt=0 t
X
in
X
out
t=0 tt=0 t TN
X
in
X
out
t=0 tt=0 t
TV
OB 250/251: Closed-Loop Control/ PID Algorithm
CPU 928B Programming Guide
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