Rockwell Automation 1771-QDC, D17716.5.87(Passport) CLAMP AND EJECT MODE - Manual (Page 196)

Tune Your Machine
Chapter 10
10-23
Clamp Position for Start of Ejector Profile (EPC61)
If “start on position” (EPC03-B08 = 0) is selected for ejector profile
execution rather than “start on command” (EPC03-B08 = 1), the QDC
module immediately begins execution of the Ejector Profile once this
position is reached during its execution of any Clamp Open Profile.
Any position greater than EPC62 is satisfactory for this clamp position,
and initiating ejector movement before the clamp is fully open has
generally become accepted in the industry as a legitimate method to be
employed by a molder attempting to reduce his overall machine cycle time.
ATTENTION: If your machine shares hydraulic flow between
the clamp and ejector manifolds, operating the two cylinders in
tandem decreases the accuracy of the valve spanning parameters
determined in chapter 9 and the tuning constants determined
earlier in this chapter. In closed-loop mode, the QDC module
will attempt 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 operation may result in unstable ejector
movement. Use extreme caution when operating the clamp and
ejector in tandem on machines that share fluid between the two
cylinders in closed loop with ERC enabled.