Rockwell Automation 1771-QDC, D17716.5.85 User Manual

Plastic Molding Module

(Cat. No. 1771-QDC)

Inject Mode

Important User Information

Because of the variety of uses for the products described in this publication,
those responsible for the application and use of this control equipment must
satisfy themselves that all necessary steps have been taken to assure that
each application and use meets all performance and safety requirements,
including any applicable laws, regulations, codes and standards.

The illustrations, charts, sample programs and layout examples shown in
this guide are intended solely for purposes of example. Since there are
many variables and requirements associated with any particular installation,
Allen-Bradley does not assume responsibility or liability (to include
intellectual property liability) for actual use based upon the examples shown
in this publication.

Allen-Bradley publication SGI-1.1, Safety Guidelines for the Application,
Installation, and Maintenance of Solid State Control (available from your
local Allen-Bradley office), describes some important differences between
solid-state equipment and electromechanical devices that should be taken
into consideration when applying products such as those described in this
publication.

Reproduction of the contents of this copyrighted publication, in whole or in
part,

without written permission of Allen-Bradley Company, Inc. is prohibited.

Throughout this manual we use ATTENTION and Important to alert you
to the following:

ATTENTION: Tells readers where people may be hurt,
machinery may be damaged, or economic loss may occur, if
procedures are not followed properly.

ATTENTION helps you:

- identify a hazard

- avoid the hazard

- recognize the consequences

Important: Identifies information that is especially important for successful
application and understanding of the product.

Important: We recommend that you frequently back up your application
programs on an appropriate storage medium to avoid possible data loss.

PLC is a registered trademark of Allen-Bradley Company, Inc.
PanelView, and PanelBuider are trademarks of Allen-Bradley Company, Inc

Summary of Changes

Summary of Changes

Summary of Changes

We revised this publication to include changes due to upgrading the
1771-QDC/B module to a 1771-QDC/C.

For These Changes Refer to Page(s)

Lossofsensor detection
input range changed back to 0.00 to 10V dc

Added the section, Record I/O Ranges.

Added the title Ground and Shield Your I/O Devices to
better describe the task.

Reversed the order of chapters 3 and 4 to present the
download procedure for the MCC block before the
download procedure for the other data blocks.

Revised the download procedure for the MCC block
(chapter 3) and for other command blocks (chapter 4).

Added data codes to Profile Block worksheets. Chapter 8 and Appendix A

Placed 2page worksheets on facing pages Chapters 7 and 8

Minor corrections as found

35, 310
A3, A4

21

29

Chapters 3 and 4

To Help You Find Changes

To help you find these changes, we added change bars as shown to the left.

Table of Contents

Summary of Changes 11. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Use This Preface P1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Manual

Objectives
Audience P2
Use
Related

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

of T

erms P2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Publications

Overview of Inject Mode 11. . . . . . . . . . . . . . . . . . . . . . . . . .

P1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

P4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter
Inject Mode Operation 11

Objectives

11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Install the QDC Module 21. . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter
Record
Set Module Jumper Plugs 22
Key Your I/O Chassis 25
Install
Wire
Ground and Shield Your I/O Devices 29
Plan for EStops and Machine Interlocks 211

Configure the QDC Module'

Chapter
Use Worksheets to Select Module Parameters and I/O Ranges 31
Determine Initial Sensorconfiguration Values 34
Download
Use SetOutput Operation to Move the Ram (Screw) 38
Complete Your Sensor Configuration 39
Select

Objectives

I/O Ranges

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

the QDC Module

the QDC Module

Objectives

MCC V

Optional Configurations

alues to the QDC Module

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s I/O

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21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

31. . . . . . . . . . . . . . . . . . . .

31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

36. . . . . . . . . . . . . . . . .

314. . . . . . . . . . . . . . . . . . . . . . . . . .

Overview of Remaining Configuration Procedures 41. . . . . .

Chapter
Configuration Concepts 41
Special Command and Status Blocks 42
Overview of Remaining Configuration Procedures 43
Enter Data Table Values and Download Command Blocks 44

Objectives

41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Table of Contentsii

Jog Your Machine 51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter
About Jogging 51
Use These Worksheets 51
Determine
Write Ladder Logic 55
Jog Your Ram (Screw) 57
Configure Jogs for the Clamp and Ejector 57
Write Ladder Logic to Assist with Clamp & Eject Jogs 59
Jog Your Clamp and Ejector 510

Objectives

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Initial Jog V

51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

alues 52. . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Select Command and Status Bits to Sequence

Machine Operation 61. . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter
Assess Your Logic Requirements 61
Use

Load

Chapter
Use These Worksheets 72
Procedure
Determine

Select the T
Set Values for Expert Response CompensationE (ERC) 715
Determine Unselected Valve Setoutput Values 715
Set Your Acceleration/Deceleration Ramp Rates 717
Determine Setoutput Values for End of Profiles 718
Set Pressure Control Limits 719
Set V
Set
Set

Enter and Download your Worksheet Values 726

Objectives

. . . . . . . . . . . . . . . . . . . . . . . .

Command and Status Bit T

Initial Configuration V

Objectives

to Determine and Enter Initial V

Bit Selections: Assign Module Outputs

for Your Control Valves 712. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ype of PID Algorithm

elocity Control Limits
RPM Control Limits
Profile T

and Watchdog Timer Preset 725

uning Constants, PressureAlarm Setpoints,

ables 62. . . . . . . . . . . . . . . . . . . . . .

alues 71. . . . . . . . . . . . . . . . . . . .

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alues 712. . . . . . . . . . . . . .

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61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

71. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

714. . . . . . . . . . . . . . . . . . . . . . . . .

722. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

723. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Load

Initial Profile V

Chapter
Use These Worksheets 81
Determine and Record Setpoints for the Injection Profile (IPC) 82
Determine Bit Selections for Worksheet 8A 84
Determine Word Values for Worksheet 8A 85
Enter and Download your Worksheet Values 89
Determine and Record Setpoints for the Pack/Hold Profile (HPC) 89
Determine Bit Selections for Worksheet 8B 812

Objectives

alues 81. . . . . . . . . . . . . . . . . . . . . . . . .

81. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Table of Contents iii

Determine Word Values for Worksheet 8B 814. . . . . . . . . . . . . . . . . .

Enter and Download your Worksheet Values 815
Determine and Record Setpoints for Plastication Profile (PPC) 816
Determine Bit Selections for Worksheet 8C 818
Determine Word Values for Worksheet 8C 819
Enter and Download your Worksheet Values 822

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Span Your V

Chapter
Referenced Worksheets 91
Span Your Injection Pressure Valve 92
Span Your Injection V
Span Your Pack and Hold Pressure Valves 913
Span Your Plastication Pressure Valve 920
Span Y

alves 91. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Objectives

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. . . . . . . . . . . . . . . . . . . . . . .

elocity V

our Plastication RPM V

alve 97. . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . .

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alve 925. . . . . . . . . . . . . . . . . . . . . . . .

91. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Tune Your Machine for Producing Parts 101. . . . . . . . . . . . . . .

Chapter
Closedloop Control 102
Tune Closedloop Pressure Control 102
Tune Closedloop V
Tuning Considerations for Production Parts 108
Profile Requirements 108
Cushion, Shot Size, and T
Unselected Valve Setoutput Values 1013
Logical Bridges and Endofprofile Setoutput Values 1015
Decompression Pullback 1016
Acceleration and Deceleration Ramp Rates 1016
Watchdog T
Pressure
Pressurelimited
Expert Response Compensation 1021

Objectives

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

elocity Control

imer and Profile Of

Alarm Setpoints

Injection V

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ransition Setpoints

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fsets 1018. . . . . . . . . . . . . . . . . . . . . . .

elocity vs. Position

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101. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

105. . . . . . . . . . . . . . . . . . . . . . . .

1011. . . . . . . . . . . . . . . .

1018. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1019. . . . . . . . . . . . . . .

Troubleshoot with LEDs 111. . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter
Use LEDs to Troubleshoot Your QDC Module 111
Module

Objectives

Calibration

111. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . .

112. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Blank Worksheets A1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Use This Preface

Preface

Manual

Objectives

Use this preface to familiarize yourself with this manual so you can use it
effectively. This manual shows you how to apply the QDC module to your
molding machine in the minimum length of time.

Since this manual is task oriented, we recommend that you perform these
tasks in the following order:

Perform this task: As discussed in this

Browse through the entire manual to become familiar with its
contents.

Overview the inject process. This presents an overview on
how the QDC module controls the inject phase of your injection
molding system.

Install the QDC module. This includes such tasks as wiring
and setting jumpers.

Configure the QDC module mode to match your specific
application, and to communicate with inputs and outputs.

Overview of remaining configuration procedures that you will
perform throughout the remainder of this manual.

Jog the ram (screw). This task requires jog setpoints to be
configured along with jog pressure alarm setpoints.

Set up communications between your PLC5 processor and
the QDC module. Select command and status bits that you will
use when writing your ladder logic.

Load your initial configuration values to the QDC module. This
task requires you to determine and enter values into
configuration blocks in preparation for chapter 9.

Load your initial machine profile setpoints to the QDC module.
This is performed in preparation for chapter 9.

Span your machine's valves for inject mode. This is done
using setoutput and openloop control.

Tune your machine for producing parts. Chapter 10

Troubleshoot problems that may occur with the QDC module. Chapter 11

Refer to this appendix for a blank copy of each worksheet
contained in this manual.

chapter:

All chapters

Chapter 1

Chapter 2

Chapter 3

Chapter 4

Chapter 5

Chapter 6

Chapter 7

Chapter 8

Chapter 9

Appendix A

P-1

Preface

Audience

Use

of T

erms

In order to apply the QDC module to a molding machine, we assume that
you are an:

injection molding professional
experienced programmer with Allen-Bradley PLC-5 processors
hydraulics designer or technician

We use these abbreviations:

Abbreviated Name: Item

QDC module 1771QDC Plastic Molding Module

PLC processor

T45 or T47
T50 or T53 terminal

ProSet 600 Software

PanelView Terminal

PLC5 Processor

1784T45 or T47
1784T50 or T53 Industrial Terminal

6500PS600
ProSet 600 Injection Molding Operator Interface Software

2711KC1 PanelView Operator Interface Terminal

The next table presents other terms we commonly use in this manual:

Term: Definition:

Selected Valve In multivalve systems, depending on the configured profile, the QDC

module controls one valve and presets the setting of the remaining
valves to produce moldingmachine profiles. We call the valve being
controlled by the QDC module's algorithms the selected valve.

Unselected Valves In multivalve systems, depending on the configured profile, the QDC

module controls one valve and presets the remaining valves to
produce moldingmachine profiles. We call the valves that are preset
with an open loop percentage setpoint the unselected valves.

Profile A group of mold/part setpoints which define a given machine operation

to the QDC module.

Command Blocks

Status Blocks Data blocks used by the QDC module to relay information to the

Profile Block Command block containing mold/part setpoints.

Configuration Block Command block containing machine setpoints.

Direct Acting Valve An analog control valve that delivers increasing velocity or pressure

Reverse Acting Valve An analog control valve that delivers increasing velocity or pressure

Data blocks downloaded from the PLC5 data table to the QDC
module to make configuration changes or to initiate machine actions.

PLC5 processor about the QDC module's current operating status.

with increasing signal input.

with decreasing signal input.

P-2

Preface

Command Blocks

Command blocks provide the parameters that control machine operation.
They are transferred from the PLC processor to the QDC module by means
of block transfer write (BTW) instructions in software ladder logic. Their
abbreviations are:

Acronym: Description:

MCC Module Configuration Block

JGC Jog Configuration Block

INC Injection Configuration Block

IPC Injection Profile Block

PKC Pack Configuration Block

HDC Hold Configuration Block

HPC Pack/Hold Profile Block

PRC Predecompression Configuration Block

PLC Plastication Configuration Block

PPC Plastication Profile Block

PSC Postdecompression Configuration Block

DYC Dynamic Command Block

RLC

Inject ERC Values Command Block

Status Blocks

Status blocks report current status of molding-machine operation. They
are returned from the QDC module to the PLC processor by means of
block transfer read (BTR) instructions in software ladder logic. Their
abbreviations are:

Acronym: Description:

SYS System Status Block

IPS Injection Profile Status Block

HPS Pack/Hold Profile Status Block

PPS Plastication Profile Status Block

RLS

Inject ERC Values Status Block

P-3

Preface

Word and bit Numbering

The QDC module stores data in command and status blocks. Each word
location in a command or status block is identified by an alphanumeric
code containing the block acronym and word number. For example, word
09 of the Module Configuration Command Block (MCC) is identified as
MCC09.

Identify bits in a word location by adding bit numbering to the abbreviated
word location. For example:

Specific: MCC09-B15 General: MCCxx-Byy

where:

MCC = Module Configuration Command Block
xx=word number (01-64)
B = bit identifier
yy = bit number (00-15)

Related

Publications

The following table lists documentation necessary for the successful
application of the QDC module:

Publication

17856.6.1 PLC5 Family Programmable

6200N8.001 6200 PLC5 Programming

17714.10 Application guide Select QDC module's mode of operation and

17716.5.86
17716.5.87
17716.5.93

17716.5.88 Plastic Molding Module

#:

Use this documentation: To:

Controller Installation Manual

Software Documentation Set

Plastic Molding Module,
1771QDC, User Manuals

1771QDC, Reference
Manual

Install the PLC processor and I/O modules.

Select instructions and organize memory
when writing ladder logic to run your machine

match it to your machine's hydraulics

Configure, program, install, and operate your
QDC module in other QDC modes of
operation

Program block transfers between PLC
processor and QDC. Also, information on
PLC5 data transfer logic.

P-4

Preface

Take time now to familiarize yourself with the Reference Manual,
publication 1771-6.5.88. The five sections, in brief, include:

summary of each data block used by the QDC module

(abbreviated command and status blocks)

programming error codes returned by the QDC module for each data

block, and recommended procedures to correct these errors

detailed listing and explanation of each command word and bit used by,

and each status word and bit returned from, the QDC module

operational, mechanical, electrical, and environmental specifications

about your module

instructions to help you calibrate your QDC module

If you purchased Pro-Set 600 software, you also need the following:

Publication

65006.5.11 ProSet 600 Software

65006.5.12 ProSet 600 Software

65006.5.13 ProSet 600 Software

65006.5.14 ProSet 600 Software

65006.5.15 ProSet 600 Software

#:

Use this documentation: To:

Designer's Guide

Assembly Manual

Overlay Installation Manual

Customization Manual

Reference Manual

Select the ProSet 600 software that matches
the requirements of your molding machine.

Transfer your ProSet 600 software from a
floppy to your hard drive. Add overlays into
your PLC5 and PanelView application files.

Install ProSet 600 overlays into your
application files to obtain desired features.

Customize your ProSet 600 application to
your machinecontrol requirements.

Support customizing your software control
system.

P-5

Chapter

Overview of Inject Mode

1

Chapter

Objectives

Inject Mode Operation

Inject Phase Description

Injection The ram (screw) injects plastic into the mold. You can vary the velocity of the ram (screw), or the pressure

This chapter presents an overview of the 1771-QDC Plastic Molding
Module in the Inject mode. We present a summary of Inject features
followed by sample applications.

Important: This manual assumes you have already read your Plastic
Molding Module Application Guide, publication 1771-4.10, and have
chosen Inject as your QDC module’s mode of operation.

The Inject mode controls the following actions of your molding machine:

Shoots hot plastic into the mold
Packs and holds the plastic until cured
Reloads for the next shot

When you select the Inject mode, you can use the following phases:

Table 1.A

of Inject Mode

Phases

driving it, to fill areas of the mold cavity at different rates to achieve uniform quality of the molded part.
This phase can be critical to part quality. The pattern of velocity or pressure variation during injection is
called the injection profile.

Transition Detects when injection is complete.

Pack
(optional)

Hold Holding lets the plastic cool and shrink slightly from the mold cavity in preparation for ejection. The affect

Pre-decompression
(optional)

Plastication The machine reloads by drawing plastic beads into the barrel containing the ram (screw). The mechanical

Post-decompression
(optional)

Packing pressurizes the plastic to a specified density which determines the flexibility of the molded part.
To achieve uniform density, you can release or increase pressure in steps according to cooling gradients
across the mold. Thus, as the plastic cools unevenly, the pack profile can compress the plastic uniformly.

is similar to packing. You can hold at predetermined pressures for predetermined lengths of time
throughout the hold phase.

This single, backward movement of the ram (screw) separates plastic solidifying in the mold from molten
cushion remaining in the barrel prior to plastication. This phase is also referred to as sprue break.

action of the rotating ram (screw) grinds and melts the beads. The longer it grinds, the hotter it melts. You
can vary the screw RPM or backpressure on the ram (screw) causing it to remain longer in an area. Thus,
you can induce any desired temperature gradient along the length of the shot.

This single, backward movement of the ram (screw) guards against drooling molten plastic into the open
mold during ejection prior to the next injection. This phase is also called melt pullback or suckback.

1-1

Chapter 1

Overview of Inject Mode

Figure 1.1

Operation of a T

Inject

ypical Machine Cycle

Clamp
& Eject
Operation

Injection Pack Hold

Post- Pre­Decompression Decompression

Transition to
Pack or Hold

Plastication

(Reload)

Injection Phase

You can vary the velocity of the ram (screw), or the pressure driving it, so
the leading edge of the melt moves through the mold cavity at the desired
speed. The pattern of velocity or pressure variation during injection is
called the injection profile. The QDC module lets you chose from four
different injection profiles:

velocity vs. position
pressure-limited velocity vs. position
pressure vs. position
pressure vs. time

1-2

11 10 9

Figure 1.2
Example

Injection Profile

87654321

Position or T

ime

Velocity
or
Pressure

You enter setpoints to create a profile. You can select from 1 to 11
segments of position or time. Segment numbers represent the order of
operation. By convention the ram (screw) injects plastic by moving from
right to left.

Chapter 1

Overview of Inject Mode

With this Profile

Velocity vs. Position Speed Length of the shot

Pressure-limited [1]
Velocity vs. Position

Pressure vs. Position Pressure Length of the shot

Pressure vs. Time Pressure Time for a shot

You Control Injection With up to 11 Segments

Speed, with a maximum
pressure

Distributed over the

Length of the shot

[1] Pressure-limited velocity vs. position profile differs from the velocity
vs. position profile as follows: During any segment of a pressure-limited
profile if the pressure exceeds a preset limit, the module switches to PID
pressure control with the pressure limit as the setpoint. Then if velocity
exceeds the velocity setpoint, the module returns to velocity control.

Example Benefits of Profiling an Injection Phase

The injection phase should force the melt through the mold as fast as
possible without flashing or burning the melt at a mold gate. Here are two
examples of how you can achieve this by profiling the injection phase.

5

43

Velocity Example – As the leading edge of melt enters mold cavities, the
flow of plastic through the gate should increase or decrease accordingly to
keep the melt front at maximum desired speed without flashing the mold.
This reduces injection time and minimizes surface stress due to surface
cooling. You achieve this by shaping the injection profile to suit the mold
cavity (figure 1.3).

Figure 1.3
Velocity

Mold Cavity

Flow into mold

Example

1

2

Gate

Mold
End

Injection

5

Sequence of execution

Profile

4

Position

Velocity

23

1

Back
Point

1-3

Chapter 1

Overview of Inject Mode

Flash Prevention Example -

With a velocity profile (figure 1.4 part 1),
the pressure may reach a peak and flash the mold at ram (screw) position
segments (part 2) that correspond to events such as:

the initial surge (2.a)
when the melt front enters a constriction in the mold cavity (2.b)

You can remedy this (part 3) by decreasing the ram (screw) velocity at
segments (3.a) and (3.b) that correspond to flash points. Conversely, you
can boost velocity at segment (3.c) where the resulting pressure is well
below the flash point. Segment pressures in part 4 are optimum for the
velocity vs. position profile in part 3.

Figure 1.4

Prevention Example

Flash

1. Initial Velocity Profile

Velocity

2. Resulting Pressure Profile

Flash
Point

Pressure

Position Position

3. Final Velocity Profile

Velocity

b ca

Position

ba

4. Resulting Pressure Profile

ba

Position

cbca

Flash
Point

Pressure

c

As an option, you may select pressure-limited velocity vs. position
injection control. With your pressure-limit setpoint below the flash point,
the module switches to pressure control prior to flashing the mold.

1-4

Chapter 1

Overview of Inject Mode

Injectiontopack Transition

The QDC module ends the injection phase and automatically starts the
pack or hold phase when it detects the first of up to four events occurred:

Ram (screw) position exceeds a preset limit
Ram (screw) pressure exceeds a preset limit
Cavity pressure exceeds a preset limit
Injection phase elapsed time exceeds a preset limit

You select which of these events you want monitored for transition by
entering the appropriate setpoint, or zero for ignoring the event. You also
may specify the zone of ram (screw) travel over which pressure transitions
may or may not occur.

Pack Phase

The QDC module controls the pack phase with a pressure vs. time profile.
You create the profile based on controlling hydraulic pressure against the
ram (screw), or by controlling pressure within the mold cavity resulting
from hydraulic pressure against the ram (screw). You can control either
pressure with up to five time segments. By convention, events occur from
right to left on the time axis (figure 1.5). You determine the pressure
setpoints and time durations for the pack profile based on molding
requirements. The pack phase is optional.

Figure 1.5

Phase Example

Pack

Pressure

4

5

Time

123

1-5

Chapter 1

Overview of Inject Mode

Lower density
(last zone filled)

Example Benefits of Profiling the Pack Phase

Molten plastic may cool unevenly in the mold causing variations in density
with the end result of warpage and distortion as shown in Figure 1.6.

Figure 1.6
Uneven

Density in Mold Cavity

Cooling in Pack Phase

Higher density
(gate zone,
greater pressure)

Pack Profile

Pressure

Gate

You can remedy this by decreasing the pack pressure with time so plastic
can back out of the mold as shown in Figure 1.7. This is to alleviate
gradations in density as the plastic cools from the low-density end of the
mold (last zone filled) to the high-density end of the mold cavity (gate
zone where pressure is greater).

Figure 1.7

Cooling in Pack Phase

Even

Constant Pressure over entire Mold Cavity

Density in Mold Cavity

Gate

5

Time

Pack Profile

5

234

Time

1

Pressure

234

1

1-6

After completing the last segment of the pack phase, the QDC module
automatically starts the hold phase.

Chapter 1

Overview of Inject Mode

Hold Phase

The QDC module controls the hold phase with a pressure vs. time profile.
You create the profile based on controlling hydraulic pressure against the
ram (screw), or by controlling pressure within the mold cavity resulting
from hydraulic pressure against the ram (screw). You can control either
pressure with up to five time segments. You determine the pressure
setpoints and time durations for the hold profile based on your molding
requirements.

After completing the last segment of the hold phase, the QDC module
either immediately starts the optional Pre-decompression movement, skips
the pre-decompression movement if none is required and immediately
starts the plastication phase, or waits for a command from your PLC
program to continue.

Predecompression Movement

You select a length of pullback for the ram (screw) prior to the plastication
phase to separate plastic solidifying in the sprue from molten cushion
remaining in the barrel.

After completing the pre-decompression movement, the QDC module
either immediately starts the plastication phase or waits for a command
from your PLC program to continue.

Plastication Phase

The plastication phase lets you achieve a melt temperature gradient in the
barrel containing the ram (screw). To do this, you can create the
plastication profile with up to 11 segments of position or time (figure 1.8).

You chose from four plastication profiles:

Backpressure vs. position
Backpressure vs. time
Screw RPM vs. position
Screw RPM vs. time

1-7

Chapter 1

Overview of Inject Mode

Figure 1.8
Plastication

Backpressure or Screw RPM

12 345

Mold End

Phase Example

hotter

6

Position or Time

Temperature Gradient

Barrel Containing the Melt

7891011

cooler

Back Point

Affects of Profiling a Plastication Phase

Backpressure and/or screw RPM have these affects on plastication:

The higher the backpressure (or screw RPM) during plastication, the

higher the resultant temperature of the melt.

You can accelerate the backup rate by reducing backpressure

(or increasing screw RPM).

You can increase resultant melt temperature by increasing backpressure

(or increasing screw RPM).

After completing the last segment of the Plastication phase, the QDC
module either immediately starts the Post-decompression movement or
waits for a command from your PLC-5 program to continue.

Postdecompression Movement

You select a length of Post-decompression pull-back of the ram (screw)
after the Plastication phase to guard against drooling molten plastic into the
open mold during ejection. The QDC module notifies your PLC-5
program when the Post-decompression movement is complete.

Screw Speed

Beginning with the 1771-QDC/C revision of the module, you can control
and monitor screw RPM only when you have configured the QDC module
for the singular Inject mode. None of the other mode combinations allow
for connecting a screw RPM sensor to the QDC module.

1-8

Chapter

Install the QDC Module

2

Chapter

Objectives

Record I/O Ranges

This chapter guides you through the following installation procedures:

record I/O ranges
set module jumpers
key your I/O chassis
install your QDC module
wire I/O devices to your QDC module
ground your system
plan for E-Stops and Machine Interlocks

To match your QDC module to your I/O devices, record the I/O ranges of
your I/O devices on Worksheet 2-A. You will use this information in this
chapter for hardware configuration (setting jumper plugs) and in chapter 4
to configure the module’s inputs and outputs with software.

Circle or check the I/O ranges on Worksheet 2-A. Cross off I/O not used.

Worksheet 2A

I/O Ranges

Record

I/O Connection: Voltage 1: Voltage 2: Current:

Input 1 (Screw position) 0 to 10 Vdc 1 to 5 Vdc 4 to 20 mA

Input 2 (Screw pressure) 0 to 10 Vdc 1 to 5 Vdc 4 to 20 mA

Input 3 (Screw RPM) 0 to 10 Vdc 1 to 5 Vdc 4 to 20 mA

Input 4 (Cavity pressure) 0 to 10 Vdc 1 to 5 Vdc 4 to 20 mA

Output 1 10 to 10 Vdc 0 to 10 Vdc 4 to 20 mA

Output 2 10 to 10 Vdc 0 to 10 Vdc 4 to 20 mA

Output 3 10 to 10 Vdc 0 to 10 Vdc 4 to 20 mA

Output 4 10 to 10 Vdc 0 to 10 Vdc 4 to 20 mA

2-1

Chapter 2

Install the QDC Module

Set Module Jumper Plugs

Before installing the QDC module, you must select with jumper plugs the
I/O ranges that you recorded on Worksheet 2-A.

Access and Position the Jumpers

Access the jumpers and set them as follows:

ATTENTION: To avoid damage to internal circuits, observe
handling precautions and rid yourself of any electrostatic
charge. Use an anti-static work station when setting jumper
plugs.

1. Remove the label-side cover plate by removing the four screws.

2. Remove the circuit board from the module housing by removing the

two screws located center-front at the swingarm catch.

3. Carefully turn over the circuit board so it is oriented as in figure 2.1.

Handle it by the edges to avoid touching conductors or components.

4. Use figure 2.1 to locate the jumper plugs.

5. Set the jumper plugs (Table 2.A) using a small needle-nose pliers.

6. After setting the jumper plugs, re-assemble the module.

2-2

Chapter 2

Install the QDC Module

Figure 2.1
Jumper

LEFT

Locations on the QDC Module'

TOP

E5

s Circuit Board

E1

E6

RIGHT

E7

E8

E9

E10

E11

E12

E15

E16

E14

E13

E17

BOTTOM

10908I

Important: We define jumper plug positions as left, right, top, and bottom.
This represents the position of the jumper plug on the 3-pin connector as
relative to the sides of the circuit board shown above.

2-3

Chapter 2

Install the QDC Module

Table 2.A
Jumper

Settings

Jumper Function Setting

E1 Run/Calibrate (Appendix G) Calibrate = right

Run = left [1]

E5 I/O Density Standard = top [1]

Do not use bottom position

E6
E7
E8
E9

E10
E14
E13
E17

E11
E12
E15
E16

[1] factoryset defaults

Input 1 (Screw position)
Input 2 (Screw pressure)
Input 3 (Screw RPM)
Input 4 (Cavity pressure)

Output 1 (Valve 1)
Output 2 (Valve 2)
Output 3 (Valve 3)
Output 4 (Valve 4)

Output 1 (Valve 1)
Output 2 (Valve 2)
Output 3 (Valve 3)
Output 4 (Valve 4)

Voltage = right [1]
Current = left

Current = top
Voltage = bottom [1]

-10 to +10VDC = top
0 to +10VDC or
4 to 20mA = bottom [1]

Important: If you select current output with jumper plugs E10, E14, E13,
and/or E17, then you must select the 4 to 20mA jumper position with E11,
E12, E15, and/or E16.

ATTENTION: If an output is unconnected, set the jumper
(E11, E12, E15, and/or E16) that corresponds to that output to 0
to 10 Vdc (bottom position). Setting the jumpers for –10 to +10
Vdc and later configuring the output as “unconnected” causes
the QDC module to output –10 Vdc on that channel when
stopped or when a system reset occurs and all outputs are forced
to 0% (i.e. 0% output equals –10Vdc).

Important: Selecting –10 to +10 VDC with jumper E11, E12, E15, and/or
E16 sets the QDC module for bi-directional valve operation. The
relationship to percentage output is as follows:

10

0

Output Voltage (Vdc)

-10

0 102030405060708090100

%Output Requested

2-4

Chapter 2

Install the QDC Module

Key Your I/O Chassis

Use the plastic keying bands, shipped with each I/O chassis, for keying I/O
slots to accept only one type of module. This is done to prevent the
inadvertent installation of the wrong module into the wrong slot.

The QDC module is slotted in two places on the rear edge of the circuit
board. The position of the keying bands on the backplane connector must
correspond to these slots to allow insertion of the module.

Place keying bands between the following terminal numbers labeled on the
backplane connector of your I/O chassis (see Figure 2.2):

between 20 and 22
between 26 and 28

Figure 2.2

Positions

Keying

2
4
6
8
10
12
14
16
18
20

Keying
Bands

22
24
26
28
30
32
34
36

Install the QDC Module

1771QDC

12676

Install your QDC module in an I/O chassis with these steps:

1. First, turn off power to the I/O chassis.

ATTENTION: Remove power from the 1771 I/O chassis

backplane and wiring arm before removing or installing a QDC
module.

Failure to remove power from the backplane could cause injury
or equipment damage due to possible unexpected operation.

2-5

Chapter 2

Install the QDC Module

Failure to remove power from the backplane or wiring arm
could cause module damage, degradation of performance, or
injury.

2. Place the module in the plastic tracks on the top and bottom of the

slot that guides the module into position.

Important: Be aware that Pro-Set 600 expects your QDC module to be
placed in slot 0 of I/O rack 0 when operating in inject mode. If you choose
to install your QDC module in some other slot, some modifications to your
PLC-5 application program will be necessary (refer to your Pro-Set 600
documentation for details).

3. Do not force the module into its backplane connector. Apply a firm

and even pressure on the module to seat it properly.

Wire the QDC Module

4. Snap the chassis latch over the top of the module to secure it.

5. Connect the wiring arm to the module.

Use the wiring arm (1771-WF) supplied with the QDC module to wire I/O
devices (Figure 2.3). The wiring arm lets you install or remove the QDC
module from the I/O chassis without rewiring. Wiring arm terminals are
numbered in descending order from the top down, starting with terminal 18
(Figure 2.3 and Table 2.B).

2-6

Figure 2.3

W

iring and Grounding

I/O

Chapter 2

Install the QDC Module

+

Customer
PS

–

+

Screw
Position
Sensor

–

+

Screw
Pressure
Sensor

–

+

Screw
RPM
Sensor

–

+

Cavity
Pressure
Sensor

–

Input 3

Input 4

Input 1

Input 2

–

Customer
PS

18

+

–

+

Amplifier
Valve 1

+

–

+

–

To Valve 1

+

–

Amplifier
Valve 2

Amplifier
Valve 3

+

–

To Valve 2

+

–

17
16
15
14
13
12

11

10
9

8
7

6

5
4

3
2
1

Output 1

Output 2

Output 3

Earth Ground

Wiring Arm
1771WF

Output 4

+

–

Amplifier
Valve 4

To Valve 3

+

–

To Valve 4

10909I

2-7

Chapter 2

Install the QDC Module

Table 2.B

T

erminal Designations

I/O

Transducer I/O Designation Terminal

Screw position Input 1 (+)

(-)

Screw pressure Input 2 (+)

(-)

Input common 14

Screw RPM Input 3 (+)

(-)

Cavity pressure Input 4 (+)

(-)

Valve 1 Output 1 (+)

Output common

Valve 2 Output 2 (+)

Output common

Valve 3 Output 3 (+)

Output common

Valve 4 Output 4 (+)

Output common

Not used 01

18
17

16
15

13
12

11
10

09
08

07
06

05
04

03
02

ATTENTION: The QDC module has ESD protection to 20KV,
but you can damage the module by accidental application of the
wrong voltage to the I/O terminals. Do not exceed:

This voltage On these terminals When in

+12vdc input (18 thru 10) any mode

+12vdc output (09 thru 02) voltage mode

+24vdc output (09 thru 02) current mode

2-8

Chapter 2

Install the QDC Module

Ground and Shield

our I/O Devices

Y

Input Sensor

Analog inputs and outputs are sensitive to electrical noise interference.
Take care to shield them properly.

Guidelines:

Use 22-gage (or larger) twisted-pair cable, 100% shielded with drain

wire, such as Belden 8761 (or equivalent). For cable distances over
50 ft, use 18-gage cable such as Belden 8760 (or equivalent)

Ground the cable shield at one end only; generally at the sensor or

amplifier end, not at the I/O chassis (see Figure 2.4 and Figure 2.5)

Figure 2.4
Shielding

Differential Inputs

QDC Module Input

18
17

18v

18v

+15V

22M

+

10G

–

22M

Connect the cable shield
and case ground to earth
ground at the Input Sensor

14

Do not connect.
Test purposes,
only.

-15V

109103

2-9

Chapter 2

Install the QDC Module

Figure 2.5
Shielding

QDC Module Output

Singleended Outputs

Customer Valve Amplifier

+

–

9

8

Connect the cable shield to earth ground
at the valve amplifier

Input
Ground
Chassis Ground

17182

ground the cable shields to a low-impedance earth ground of less than

1/8 ohm

do not connect any ground to input common (terminal 14) except as

specified below under Grounding Exceptions

place high-voltage Class A wiring and low-voltage class B wiring in

separate grounded conduits

in parallel runs, separate the Class A and B conduit by at least 1 foot

where conduit runs must cross, cross them at right angles

For additional grounding recommendations, refer to the Allen-Bradley
Programmable Controller Wiring and Grounding Guidelines, publication
1770-4.1.

Exceptions

If you experience unacceptable electrical noise interference, then try one or
both of the following alternative grounding connections:

connect the input cable shield to input common (terminal 14) after

disconnecting the shield from the transducer

connect the output cable shield to output common (terminals 8, 6, 4,

and/or 2) after disconnecting it from the valve amplifier

2-10

Chapter 2

Install the QDC Module

Plan for EStops and
Machine Interlocks

You must consider the installation of Emergency Stop (E-STOP) switches
and machine interlocks when you:

design your system

assemble mechanical/hydraulic components

wire system components

develop system ladder logic

ATTENTION: The Electrical Standard for Industrial
Machinery (NFPA 79-1987) requires an emergency stop that
when actuated, shall de-energize all electrical power circuits
which provide electrical energy to sustain machine motion.
Maintained contact “Emergency Stop” push buttons are
recommended.

ATTENTION: The American National Standard for Plastics
Machinery -- Horizontal Injection Molding Machines -- for
Construction, Care, and Use (ANSI B151.1-1984) requires
hydraulic, mechanical, and electrical interlocks to prevent
inadvertent clamp closing with a safety gate in an open position.

In addition, we strongly recommend that the electrical
interlocks consist of redundant devices and that the control
circuit be so arranged that malfunction or improper sequencing
of either redundant device prevents further operation of the
machine.

ATTENTION: NEMA Standards Publication ICS1.1, Safety
guidelines for the Application, Installation, and Maintenance of
Solid State Control recommends that the emergency stop and
safety gate electrical interlocks should directly control their
appropriate functions through an electromechanical device
independent of the solid state logic.

The next page shows an illustration of a typical grounded PLC power
distribution circuit. For ungrounded systems or for more information on
grounding and wiring guidelines, refer to Allen-Bradley publication
1770-4.1, Programmable Controller Wiring and Grounding Guidelines.

2-11