INSTALLATION
Series 642
42/113
Edition 2017-11-24
605593EC
4.6.9
Pressure control algorithem
•
Local operation:
o
With CPA direct setup, see chapter: With CPA 3.0 direct setup
(standard).
o
With CV or CPA, go to «Tools» > «Terminal» and send setup commands
according to application needs. See next tables.
4.6.9.1
Adaptive control algorithm (downstream)
Parameter
Command
Request
Data Type
Values
SENSOR DELAY
Set
s:02A00c
s:02
FLOAT
c = 0.00…1.00
Default is: 0.00 s
Get
i:02A00
i:02A00c
RAMP TIME
Set
s:02A01c
s:02
FLOAT
c = 0.00…1
’
000
’
000.0
Default is: 0.00 s
Get
i:02A01
i:02A01c
RAMP MODE
Set
s:02A02c
s:02
UINT
c = 0 or 1
0 = constant time
1 = constant slope
Default is: 0
Get
i:02A02
i:02A02c
GAIN FACTOR
Set
s:02A04c
s:02
FLOAT
c = 0.0001…7.5
Default is: 1.0
Get
i:02A04
i:02A04c
Explanation:
SENSOR DELAY
Sensor response time [s]
The SENSOR DELAY is a control parameter to compensate delays during the pressure detection. Pipes and orifices for
sensor attachment can cause delays in response time and could impact badly the 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.
RAMP TIME
Pressure setpoint ramp time [s]
RAMP MODE
Mode = 0
Cocnstant Time
The RAMP TIME is dependent on the adjusted parameter ramp time and is always the
same independent of the control deviation. That means the ramp time from the actual
value to the setpoint value is the adjusted parameter ramp time value.
Mode = 1
Constant Slope
The RAMP TIME is dependent on the adjusted parameter ramp time and is different
depending on the control deviation. The RAMP TIME is calculated corresponding to the
sensor full scale value (10V). Ramp time = 10 sec.; ramp time slope is SFS (10V) in 10
Seconds.
In the adaptive pressure controller mode, the RAMP TIME parameter also can be a value to minimize
over- / undershooting. The ramp could be used to harmonize the adaptive control algorithm.