Rockwell Automation 1771-QDC, D17716.5.87(Passport) CLAMP AND EJECT MODE - Manual (Page 182)

Tune Your Machine
Chapter 10
10-9
Enter an operational profile representative of the movement characteristics
you desire for your production cycle. Zero the appropriate velocity
feedforward term(s) associated with the profile(s), leaving the proportional
term(s) at the default settings you entered in chapter 7.
Run several cycles of the profile(s) while observing the profile actuals
returned in the appropriate status block. Also pay attention to the
hydraulic hoses leading to the cylinder being controlled.
If: Then:
Observed actuals are consistently well below
profile setpoints
Increase proportional term(s)
Observed actuals are consistently well above
profile setpoints
Decrease proportional term(s)
Excessive hammering and vibration is
observed in the cylinder's hydraulic lines
Decrease proportional term(s)
Important: Each change to a tuning constant requires you to download
your changes to the QDC module. Refer to the Download Procedure
outlined in chapter 4.
Repeat the profile(s) cycles after each change to the proportional term(s)
until observed actuals are close to setpoints without hammering and
vibration in the controlling cylinder’s hydraulic lines.
If you cannot make your observed velocity actuals match your 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).
If you are satisfied with your Unselected Valve Set-output Values and still
cannot match your observed velocities to the desired setpoints, your
control may require a small feedforward gain. Without modifying the
proportional term(s) determined by the above procedure, slowly begin
increasing the appropriate velocity feedforward term(s) while running
machine cycles until the observed profile velocity actuals are satisfactorily
close to the entered setpoints.
Important: Do not enable ERC if you must use velocity feedforward
gain(s) to adequately tune your velocity profile(s).