Endress+Hauser Liquiline System CA80PH, Руководство по эксплуатации

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Operation Liquiline System CA80PH
122
Hauser
Controller type Options
• PID 1-sided
• PID 2-sided
Factory setting
PID 2-sided
Depending on the actuator connected, you influence the
process in just one direction (e.g. heating) or in both
directions (e.g. heating and cooling).
A 2-sided controller can output a manipulated variable in the range from -100% to +100%, i.e. the manipulated variable
is bipolar. The manipulated variable is positive if the controller should increase the process value. In the case of a pure P
controller, this means that the value of the controlled variable x is smaller than the set point w. Conversely, the
manipulated variable is negative if the process value should be decreased. The value for x is greater than the setpoint w.
The following graphic illustrates the relationship y = (w-x)/X
p
:
Effective direction
Controller type="PID 1-sided"
Options
• Direct
• Reverse
Factory setting
Reverse
In what direction should the controller influence the
measured value?
• The measured value should increase as a result of
dosing (e.g. heating) --> "Reverse"
• The measured value should decrease as a result of
dosing (e.g. cooling) --> "Direct"
A 1-sided controller has a unipolar manipulated variable, i.e. it can only influence the process in one direction. If the
controller should increase the process value, set "Reverse" as the direction of action. The controller then becomes active
when the process value is too small (range A).
With the "Direct" effective direction, the controller acts as a "downwards controller". It becomes active when the process
value (e.g. the temperature) is too high (range B).
The red curve shows overlap between the curves of the two 1-sided controllers.
Path: Menu/Setup/Additional functions/Controller 1 or Controller 2
Function Options Info