Installation, Operating & Maintenance Instructions
Series 650 DN 100-
250 (I.D. 4“ - 10”), DeviceNet
VAT Vakuumventile AG, CH-9469 Haag, Switzerland
Tel +41 81 771 61 61 Fax +41 81 771 48 30 [email protected] www.vatvalve.com
266341ED
2012-07-13
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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
:
(Refer to chapter «Explicit messaging setup
commands» for details)
Go to „Setup / Controller‟ menu.
Select sensor delay.
Select PID CONTROLLER SENSOR DELAY
3.10.2.3 Setpoint ramp adjustment
Setpoint ramp effects:
Undershoot of pressure
Response time
Default value for
Setpoint Ramp
is 1. Adjustment range for
Setpoint Ramp
is from 0 to 10 s.
This parameter defines the time that is used to decrease / raise pressure between 2 setpoints. Especially in pressure
decrease situations at low flows pressure response can be improved much by adapting setpoint ramp time.
Pressure chart
