GOSSEN-METRAWATT GMBH 35
1)
If one of the times T
I
or T
II
is considerably longer than the other one, the value for tu is too high.
Correction with limitation of the regulation ratio YH positive: Multiply Pb I by 100 % / YH
YH negative: Multiply Pb II by –100 % / YH
Correction for step controller if one of the times T
I
or T
II
is smaller than tY:
tY
• tY tY • tY
Multiply Pb I by , if T
I
is smallest, multiply by , if T
II
is smallest
T
I
• T
I
T
II
• T
II
The value for tu is very inaccurate in this case. It should be re-optimized in control operation.
Control operation
After optimizing is ended, the controller can be used:
– Configure the desired control algorithm with Controller type.
– Set the set point to the required value.
– For three-state, split range and step controllers, the deadband can be increased from dbnd = 0 should the control of the switching outputs I
(and/or continuous output) and II change too fast due to an instable actual value.
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