Endress+Hauser Liquiline CA80SI - Page 98

Operation Liquiline System CA80SI
98 Endress+Hauser
Menu/Setup/Additional functions/Controller 1 ... 2
Function Options Info
Measured value Selection
Depends on Source of data
Factory setting
None
‣
Specify the measured value that should be
your disturbance variable.
You can use different measured values
depending on the data source.
Zp Range of adjustment
depending on the selection
of the measured value
Proportional band ‐‐>
Z0 Zero point
Parameters
The Liquiline PID controller has been implemented in the serial structural form, i.e. it has the following
parameters:
• Integral action time T
n
• Derivative action time T
v
• Proportional band X
p
Setup Level = Advanced: With this setup level, you can also configure the following:
• Time constant T
wu
• Time constant α
• Width of the neutral zone X
n
• Width of the hysteresis range of the neutral zone X
hyst
• Clock time of the controller
Tn 0.0 to 9999.0 s
Factory setting
0.0 s
The integral action time specifies the effect of
the I-value
If Tn > 0 the following applies: Clock < Twu <
0.5(Tn + Tv)
The integral action time is the time needed in a step-function response to achieve a change in the manipulated
variable - as a result of the I effect - which has the same magnitude as the P-value.
y
t
PI
P
T
n
e
t
0
0
e = control deviation, e=w‐x (set point controlled variable)