Ransburg DynaFlow User Manual - Manual (Page 62)

LN-9400-00.9
DynaFlow TM User Manual - Operation
58
Recommended to start with these values and
confirm stable response before trying to achieve
faster response from the system. Generally,
when adjusting the Proportional (Kp) and Integral
(Ki) gain parameters, adjust both up or down pro-
portional to themselves. In other words, if faster
response is desired and the system is currently
operating stable, assume the starting Kp value is
500 and the starting Ki value is 2000. You would
adjust the Kp value to 550 (10% increase) and
the Ki value to 2200 (also a 10% increase). The
deadband parameter should be kept to 1 and the
differential gain (Kd) at 0.
Quick triggering applications: For applications
requiring multiple, short trigger cycles, more
stable response can typically be obtained by
adjusting the Kp down to approximately 75-100,
while adjusting the Ki to approximately 1000-2500.
2. The Integral gain is probably the most impor-
tant setting and has the greatest overall impact
on response behavior associated with the fluid
flow control system. This parameter can also be
adjusted through a relatively large range without
creating instability.
3. The Proportional gain can improve system
response, especially for large set point changes,
but care should be taken not to increase by more
than approximately 25% of the default setting. The
system can easily become unstable and go into
oscillation if adjusted to high.
4. The differential gain has the least effect on
system performance and should be left at the
default setting of zero (0).
5. Response times will be limited by changes in
the fluid mechanics of the system. It will take
longer to achieve requested flow rate as fluid
viscosity increases or fluid supply pressure de-
creases. In other words, the same response cannot
be achieved for a 50 sec, Zahn #2 material as for
a 20 sec, Zahn #2 material given the same fluid
supply pressure and fluid control components.
This is important to understand, especially for 2K
systems. It may be an advantage to purposely
slow down the response of the quicker reacting
(thinner) fluid such that it will remain closer to that
of the thicker fluid in 2K systems during triggers
or changes in the set point. Other options are to
decrease the supply pressure for the thinner fluid
or increase pressure for the thicker fluid.
6. "Reset Windup" condition. Reference "Trouble-
shooting" in the "Maintenance" section. Reset
windup is a condition when the controller does not
have enough strength to reduce the error back to
zero. This occurs due to unusual restrictions in
the fluid control devices or fluid lines and indicates
that the system is not tuned properly or there is
a problem. If the actual fluid flow is less than the
requested flow (minus the dead band value), the
controller will continue to increase the output until
it reaches the maximum allowable fluid regulator
Fluid
Regulator
MVR #2
MVR #3
MVR #4
DR1, 1:1
DR1, 1:2
DR1, 1:3
DR1, 1:4
DR1, 1:6
DR1, 1:8
DR1, 1:10
10
15
20
50
45
40
35
30
25
20
Kp Ki
1200
1000
800
1000
1200
1400
1600
1800
2000
2200
DEFAULT CONTROL
PARAMETERS
Fluid
Regulator
MVR #2
MVR #3
MVR #4
DR1, 1:1
DR1, 1:2
DR1, 1:3
DR1, 1:4
DR1, 1:6
DR1, 1:8
DR1, 1:10
0-500
0-500
0-500
0-500
0-500
0-500
0-500
0-500
0-500
0-500
Kp Typical
Range
Ki Typical
Range
600-2400
500-2000
400-1600
500-2000
600-2400
700-2800
800-3200
900-3600
1000-4000
1100-4400
TYPICAL RANGES FOR
CONTROL PARAMETERS