Ransburg DynaFlow User Manual - Manual (Page 64)

LN-9400-00.9
DynaFlow TM User Manual - Operation
60
16. Trigger the GUN. If the flow rate does not
oscillate, or the oscillations decrease in amplitude
in a few seconds, increase Kd by 30 and repeat
from step 15. If the flow rate oscillates with increas-
ing amplitude, decrease Kd by 15 and repeat from
step 15. If the flow rate oscillates with a constant
amplitude, proceed to step 17.
17. Set Kd to one-eighth the present value.
18. Cycle the GUN from READY to RUN so the
new parameters are sent to the Channel Module(s).
19. At this point, the tuning procedure is com-
pleted. The resulting Kp, Ki, and Kd parameters
should produce the fastest response with minimal
over-shoot and/or oscillation. If oscillation does
occur with these PID parameters,consider re-
ducing each value by the same percentage. This
will lower the overall gain resulting in a slightly
longer time to achieve the desired set point and
a slow- er response to disturbances, such as paint
pumps.
20. For two-component GUNs, repeat steps 4
through 19 for the Slave CHANNEL.
PID Tuning Methods - Alternate PID
1. Set the maximum set point for the GUN.
2. Set Ki and Kd parameters to zero. Do this for
both CHANNELS if this is a two-component GUN.
3. Set Kp for the Master CHANNEL based on the
following formula:
(8.0 - MVR LOW) * 25,500
Kp = 10
(Max. Gun Set Point * Ratio)
(Ratio + 1)
For example:
Max. Gun Set Point = 400 cc/min.
MVR LOW = 15 PSIG
Ratio = 3:1
(8.0 - 15) * 25,500
Kp = 10
(400 * 3)
( 4 )
= 6.5 * 25,500
300
= 552.5
= 550
4. Set Kp for the Slave CHANNEL based on the
following formula:
(8.0 - MVR LOW) * 25,500
Kp = 10
(Max. Gun Set Point)
(Ratio +1)
For example:
Max. Gun Set Point = 400 cc/min.
MVR LOW = 15 PSIG
Ratio = 3:1
(8.0 - 15) * 25,500
Kp = 10
(400)
( 4 )
= 6.5 * 25,500
100
= 1657.5
= 1660
5. Cycle the GUN from READY to RUN so the new
parameters are sent to the Channel Module(s).
6. Trigger the GUN. If the flow rates do not achieve
their individual CHANNEL set points, adjust the
upstream fluid pressures until they both are on
target.
NOTE: This may require repeated triggers and
fault resetting. Once the proper fluid pressures
are set, the maximum set point for the gun will be
flowing, ratioed properly between the CHANNELS,
with the MVR pressures at 80 PSIG.