Valve Position Control; Chamber Pressure Control; Operation With 2 Sensors - VAT 650 Series Installation, Operating, & Maintenance Instructions

3.9

Valve Position Control

Mode
POSITION CONTROL

3.10 Chamber Pressure Control

Mode
PRESSURE CONTROL

3.10.1 Operation with 2 Sensors

If 2 sensor operation is enabled changeover is done automatically. For configuration refer to chapter «Setup procedure».
We recommend a ratio of 10:1 between the pressure gauges. Max. ratio is 100:1. Whereas low range pressure gauge
has to be connected to sensor 1 input and high range pressure gauge to sensor 2 input.
Between 90 and 100% of the low range sensor full scale, low range sensor is faded out while high range sensor is faded
in. This prevents from pressure leaps during sensor transition that may be caused by pressure variations between the two
sensors.
VAT Vakuumventile AG, CH-9469 Haag, Switzerland
Tel +41 81 771 61 61 Fax +41 81 771 48 30 CH@vatvalve.com
Installation, Operating & Maintenance Instructions
Series 650, DN 250 (I.D. 10"), RS232
Description
The valve position is directly controlled according to the position SETPOINT.
Execute following steps:
Local operation via service port:
1. Set position SETPOINT value
Description
The included PID controller controls the chamber pressure according to the pressure
SETPOINT by means of the valve position. The PID controller works with an adapting
algorithm to achieve best results under altering conditions (gasflow, gas type).
Perform complete «Setup procedure» to prepare the valve for PRESSURE
CONTROL.
Based on this, the PID controller is able to run fast and accurate pressure control
cycles.
Execute following steps:
Local operation via service port:
1. Set pressure SETPOINT value
Remote operation via RS232 command
on interface port (refer to chapter «RS232
control commands» for details):
Remote operation via RS232 command
on interface port (refer to chapter «RS232
control commands» for details):
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2010-04-17