Rockwell Automation 1771-QDC, D17716.5.85(Passport) MNL. PLASTIC MOLDING MODULE User Manual

Page 141

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Span Your Valves

Chapter 9

9-24

What You Have Accomplished

The open-loop tuning procedure you just completed has defined the:

range of ram (screw) backpressure during plastication

end-of-range maximum and minimum signal levels for linear control of

the plastication pressure valve in open-loop control

For this

range limit

When trying to obtain

the pressure in:

The QDC module drives the selected

pressure valve to % output signal in:

Minimum

PLC41

PLC43

Maximum

PLC42

PLC44

Now for open-loop plastication profiles, the QDC module assumes a liner
relationship between backpressure and signal output.

Set the Profile Pressure Alarm

After spanning your plastication pressure valve, set the maximum pressure
alarm setpoint PLC57 (N44:413) equal to a ram (screw) backpressure that
should not be exceeded during the plastication profile. Make sure this
value is not greater than PLC42 (N44:398) Maximum Pressure Control
Limit. Entering zero disables this alarm.

Download the PLC and PPC blocks to the QDC module.

Important: If downloading from your programming terminal, you must
download PLC first, followed by PPC.

To download

Set

PLC

B21/13

PPC

B21/14

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