VAT Series 651 - Page 26

Installation, Operating & Maintenance Instructions
Series 651 DN 320-400 (I.D. 12“ - 16”), Logic
VAT Vakuumventile AG, CH-9469 Haag, Switzerland
Tel +41 81 771 61 61 Fax +41 81 771 48 30 CH@vatvalve.com www.vatvalve.com
267736ED
2008-02-26
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3.10.2.1 Gain factor adjustment
The gain factor effects:
• Stability
• Response time
Default value is 1. Adjustment range is from 0.0001 to 7.5.
Higher gain results in: faster response higher over- / undershoot of pressure
Lower gain results in: slower response lower over- / undershoot of pressure
Adjustment procedure:
1. Start with gain factor 1.0
2. Open valve.
3. Control a typical pressure / flow situation.
4. Repeat from step 2 with lower (higher) gain factors until optimal pressure response is achieved and stability is ok.
Note: Normally adjustments down to gain factors of 0.42 should lead to good results. Otherwise you may need to
improve sensor connection. Refer to «Requirements to sensor connection».
Local operation:
(‘Control View’, ‘Control Performance Analyzer’ or
‘Service Box 2‘)
Remote operation:
Do configuration in menu ‘Setup / Control Parameter’.
Note: It’s not possible to do ‘Interface configuration‘
via remote operation.
3.10.2.2 Sensor delay adjustment
Sensor delay adjustment effects:
• Stability
Default value is 0. Adjustment range is from 0 to 1.0s.
Pipes and orifices for sensor attachment delay response time and so badly impact pressure control stability.
By adapting this parameter to the approximate delay time stability problems can be reduced. But control response time will
be slowed down by this measure.
Note: Whenever possible sensors should be attached to the chamber according to «Requirements to sensor connection».
This is the most effective measure against stability issues. If your gauge attachment fulfills these criteria do not use this
parameter.
Adjustment procedure:
1. Start with gain factor 1.0 and sensor delay 0s.
2. Open valve.
3. Control a typical pressure / flow situation.
4. Repeat from step 2 with higher sensor delays until best possible stability is achieved.
5. Adjustment gain factor again. Refer to «Gain factor adjustment».
Local operation:
(‘Control View’, ‘Control Performance Analyzer’ or
‘Service Box 2‘)
Remote operation:
Do configuration in menu ‘Setup / Control Parameter’.
Note: It’s not possible to do ‘Interface configuration‘
via remote operation.