INSTALLATION
Series 642
50/113
Edition 2017-11-24
605593EC
4.7.1.3
Setpoint ramp adjustment
Setpoint ramp effects: Undershoot of pressure, Response time
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
Without setpoint ramp optimizing
With setpoint ramp optimizing
t = Setpoint Ramp
Adjustment procedure:
1. Start with optimal gain factor and sensor delay time according to preceding tuning steps.
2. Control a typical pressure / flow situation.
3. Control a lower pressure.
4. Repeat from step 2 with longer setpoint ramps until best response is achieved.
5. Verify pressure control response for a setpoint raise situation.
In case a long ramp time is required to get optimal performance for pressure
decrease situations it may be of advantage to apply different settings for decrease /
raise control situations.
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 / Control Parameter’ menu.
Select setpoint ramp.
Send
PID CONTROLLER CONFIGURATION RAMP
TIME
