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

Page 244

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Tune Your Machine

Chapter 10

10-16

Logical Bridges

In chapter 8, you configured your hold and plastication profiles to stop and
set outputs for no flow or pressure at completion. If your hydraulics and/or
process require NO changes controlled by your PLC-5 processor before
continuing a molding cycle, you may configure the QDC module to
logically bridge the following profile/movement pairs as integrated
machine phases:

hold/pre-decompression (HPC03-B08 = 0)
pre-decompression/plastication (HPC03-B09 = 0)
plastication/post-decompression (PPC03-B08 = 0)

Important: The QDC module always logically bridges the injection, pack
and hold phases as a single integrated machine movement.

Bridging machine phases has benefits such as:

reduced cycle time
smoother QDC control
less chance of hydraulic pressure transients

If your hydraulics and/or process require changes controlled by your
PLC-5 processor before continuing a molding cycle, you may configure
the QDC module to stop at completion of:

hold (HPC03-B08 = 1)
pre-decompression (HPC03-B09 = 1)
plastication (PPC03-B08 = 1)

Then the QDC module sends a fixed signal to each of its four outputs
while awaiting further commands from the PLC-5 processor.

Important: The QDC module always stops and sets outputs at completion
of the post-decompression movement.

EndĆofĆprofile SetĆoutput Values

End-of-profile set-output values have uses including:

adjusting flow through a variable pump between profiles
initializing valves for the next profile or movement
re-aligning solenoid valves by PLC-5 processor before starting the next

profile or movement

When configuring end-of-profile set-output values, remember:

The QDC module ignores these values on all profiles that are logically

bridged to the next profile or movement

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