Rockwell Automation 1771-QDC, D17716.5.93(Passport) PLASTIC MOLDING MODULE - Manual (Page 257)

Tune Your Machine
Chapter 10
10-29
Important: If you change tooling or set-up which results in changing
either of these two distances, you must recalculate clamp position EPC62.
Clamp Position for Start of Ejector Profile (EPC61)
If you select to start the ejector profile on position (EPC03-B08 = 0) rather
than on command (EPC03-B08 = 1), the QDC module immediately begins
executing the ejector profile once the clamp reaches this position during
any clamp open profile.
Any position greater than EPC62 is satisfactory for this clamp position.
Starting ejector movement before the clamp is fully open has industry
acceptance as a legitimate method to reduce overall machine cycle time.
If your machine shares hydraulic flow between clamp and ejector
manifolds, operating the two cylinders in tandem decreases the accuracy of
valve spanning parameters determined in chapter 9
tuning constants determined earlier in this chapter
In closed-loop mode, the QDC module attempts to fully open both the
ejector and clamp flow valves to maintain velocity setpoints. When the
clamp reaches the full open position and full flow is again made available
to the ejector, closed-loop ejector operation may become unstable.
ATTENTION: Use extreme caution when operating the clamp
and ejector in tandem on machines that share fluid between the
two cylinders in closed-loop, especially with ERC enabled.
Unstable operation could result in unpredictable operation with
possible equipment damage and injury to personnel.
Logical Bridges
In chapter 8, you configured your QDC module to logically bridge all your
clamp profiles. This forced the QDC module to start each successive
profile at completion of the previous one in each direction of movement.
If your hydraulics and/or process require NO changes between profiles
controlling clamp motion, you may configure the QDC module to logically
bridge the clamp open and close profiles as integrated machine phases:
first clamp close to second clamp close (CPC03-B08 = 0)
second clamp close to third clamp close (CPC03-B09 = 0)
third clamp close to low pressure close (CPC03-B10 = 0)
first clamp open to second clamp open (OPC03-B08 = 0)
second clamp open to third clamp open (OPC03-B09 = 0)
third clamp open to open slow (OPC03-B10 = 0)