wtw DIQ/S 182-XT-4, Operating Manual

Page: 120 / 152

Outputs System 182-XT-4
6 - 28 ba75753e06 12/2014
6.5.3 PID controller
Function The PID controller function can use an output as a controller output.
The controller can be configured as a Proportional controller with a
switchable Integral and Differential controller parts (PID controller).
The control response of the PID controller is described by the following
formula:
with:
The adjustable control parameters are x
set
, I
0
, X
p
, I
min
, I
max
, ti and td
(see setting table on page 6-31).
I
Controller
Current on the controller output at time t
I
0
Current on the output if x
actual
= x
set
K Amplification
X
p
Proportional range
x
e
Control difference
x
act
Actual value (current measured value)
x
set
Set value
ti Integral algorithm
td Differential control part
t Time
I
min
Lower current limitation
I
max
Upper current limitation






+ + + =

dt
dx
T dt x
T
1
x K I I
e
d e
i
e 0 Controller
p
min max
X
I I
K
−
=
act set e
x x x
− =
max Controller min
I I I
≤ ≤