Rockwell Automation 1771-QDC, D17716.5.86(Passport) PLASTIC MOLDING MODULE - Manual (Page 212)

Tune Your Machine
Chapter 10
10-4
3. Downloaded all setpoint changes to the QDC module.
4. Run several cycles of the profile while comparing profile actuals
(returned in the corresponding status block) with profile setpoints.
Also look for abnormal flexing or pulsing of hydraulic hoses leading
to the controlled cylinder.
If: Then:
Observed actuals are consistently well below
profile setpoints
Increase the proportional term
Observed actuals are consistently well above
profile setpoints
Decrease the proportional term
Excessive hammering and vibration is
observed in the cylinder's hydraulic lines
Decrease the proportional term
Important: Each time you change a gain constant, you must download the
change to the QDC module. Refer to the download procedure in chapter 4.
5. Re-run the profile after each change to the proportional term until
actuals are close to setpoints, and there is no hammering and
vibration in hydraulic lines to the controlled cylinder.
6. Slowly increase the integral term while running machine cycles until
profile pressure actuals overshoot profile setpoints. Now decrease the
integral term until overshoot disappear.
Important: If you cannot make pressures actuals match entered setpoints,
verify your unselected valve set-output values are correct for your
application (Refer to chapter 7 and the discussion later in this chapter).
Tune Pressure Loops With An Oscilloscope
Before you begin tuning your pressure loops, confirm that you:
selected the pressure vs. position algorithm
selected closed-loop control
disabled
ERC
reset ERC values
disabled
ramping
ATTENTION: Verify that you have correctly set the following
words and bits in CPC and OPC that control zone overrun to
guard against damaging the clamp or mold.
CPC03-B11 = 0: Execute low pressure close if zone overrun occurs
set CPC61 to a value larger than normal for a larger mold-protect zone
OPC03-B11 = 0: Execute open slow if zone overrun occurs
set OPC61 to a value smaller than normal for a larger open-slow zone