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Installation, Operating & Maintenance Instructions
Series 615 DN 40 (I.D. 1.5”), RS485
VAT Vakuumventile AG, CH-9469 Haag, Switzerland
Tel +41 81 771 61 61 Fax +41 81 771 48 30 [email protected] www.vatvalve.com
289111EB
2013-02-05
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1.3
Optimizing I gain
While optimizing I gain, the gas flow determined above has to be constant all the time.
Start with P gain set to half of the value found when optimizing P gain and set I gain to 1.0.
Keep the P gain constant.
Set chamber pressure to SP2, wait until the pressure is stable. Set pressure to SP1. If the transition from SP2 to SP1
results in a significant pressure over shoot or if the valve position does not stabilize, I gain is to high. If the transition
results in a slow asymptotical pressure rise and there is still a constant deviation to SP2, the I gain is too low.
The optimal value for I gain is found if the transition from SP2 to SP1 result in just a slight pressure over shoot, a stable
valve position and the actual pressure matches SP2 exactly.
Example:
Note:
Check control performance over the whole control range with parameters above.