VAT 615 Series

Installation, Operating & Maintenance Instructions
Series 615 DN 40 (I.D. 1½”), DeviceNet
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
603476EA
2013-07-25
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5. Calculate gas flow for learn with Pmax >1mbar.
q
max +
q
min
q
L
=
2
q
L
gas flow for learn
q
max
max. process gas flow
q
min
min. process gas flow
P
L
= P
max
Note:
If P
L
> P
sfs
the learn flow must be calculated according step 4 with P
sfs
instead of P
max
.
q
L
= 39.5 P
sfs
C
R
q
L
gas flow for learn [sccm]
P
sfs
sensor full scale [Torr]
C
R
required lower conductance [l/s]
3.6.7.2 Fixed algorithm
For the fixed algorithm there are 2 configurations possible, Fixed PI downstream and Fixed PI upstream. It is possible to
switch between Fixed PI downstream and Fixed PI upstream. Refer to chapter: «Pressure control algorithm» for details.
Fixed algorithm is used if for any reason (e.g. too long system time constant) the adaptive control mode does not provide
satisfying control performance.
In Fixed algorithm the parameters P-Gain and I-Gain have to be set according to the systems characteristics.
This valve may be used for downstream or upstream pressure control depending on configuration. The Fixed algorithm
parameters of the pressure controller require correct adjustment. These parameters must be set once during system setup
and are stored in the device memory which is power fail save. Based on the Fixed algorithm controller configuration, the
valve is able to run fast and accurate pressure control cycles. The Fixed algorithm parameters can be evaluated using
below instruction.
Note: In downstream control direction valve will move towards open when current pressure is higher then set point.
In upstream control direction valve will move towards close when current pressure is higher then set point.
Local operation:
‘Control View’ or ‘Control Performance Analyzer’
Remote operation:
Go to ‘Tools / Terminal’ menu and do the «Pressure
control configuration» refer to chapter: 3.6.7 Pressure
control configuration.
Note: It’s not possible to do «Pressure control
configuration» via remote operation.
Note: To optimize Fixed algorithm of pressure controller refer to chapter «Tuning of pressure control performance».