Rockwell Automation 1771-QDC, D17716.5.87(Passport) CLAMP AND EJECT MODE - Manual (Page 186)

Tune Your Machine
Chapter 10
10-13
Expert Response Compensation Minimum Percentages
Expert Response Compensation minimum percentages are utilized by the
QDC module only when ERC is enabled. Leave these entries at the default
values recommended in chapter 7 if you have decided not to enable ERC
control. The ERC percentage minimum percentage tells the QDC module
to what extent to utilize ERC from machine cycle to cycle. If you require
ERC control of your clamp or ejector, consider the following:
If ERC is enabled (on) and: Then:
The actual velocity or pressure reported in
the appropriate status block swings wildly
around the setpoint from cycle to cycle
Decrease ERC minimum %
The actual velocity or pressure reported in
the appropriate status block takes several
cycles to achieve the desired setpoint
Increase ERC minimum %
Unselected Valve SetĆoutput Values
In chapter 7 of this manual, guidelines were presented to assist you in
determining Unselected Valve Set-output Values (words 09 through 12 in
configuration command blocks) prior to spanning your machine valves in
chapter 9. The percent signal output values in these words are the signal
level sent to all outputs that are not selected to be under control of the
QDC module’s algorithm during each respective profile.
You were instructed in chapter 7 to enter values into these words that were
representative of the signal output percentages required to drive the
unselected valves during the respective profiles. These default values that
you selected should be sufficient to allow you to obtain the desired clamp
and ejector control. Although different part set-ups and other process
considerations may require that you modify your Unselected Valve
Set-output Values during a particular profile (stroke), these setpoints
normally need adjustment only if you are unable to obtain your desired
closed-loop control by modification of the appropriate profile (stroke)
tuning constants.
Important: Unselected Valve Set-output Values should be changed only
after attempting to achieve desired closed-loop control by adjusting the
appropriate profile (stroke) tuning constants.
Important: Large changes to your Unselected Valve Set-output Values
may require re-spanning the selected valve for that profile. Reference
chapter 9 for detailed valve spanning procedures.