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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
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2013-02-05
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1.2
Optimizing P gain
While optimizing P gain, the gas flow determined above has to be constant all the time.
Start optimization with P gain set to 1.0 and I gain set to 0.0.
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 even does not stabilize at all, the P gain is too high. If there is no over sho ot
and the pressure reaches SP1 asymptotically and very slow, P gain is too low.
The optimal P gain value is found if the transition from SP2 to SP1 results in a slight pressure over shoot. It does not
matter if there is still a deviation between SP1 and actual pressure.
Example: