Rockwell Automation 1771-QDC, D17716.5.86(Passport) PLASTIC MOLDING MODULE - Manual (Page 150)

Load Initial Profile Values
Chapter 8
8-29
Cushion Size
(PPC61)
This word determines the length of molten plastic that should remain in the
barrel at the conclusion of the hold profile. The QDC uses this length in
computing the 100% shot size. Units are inches or millimeters.
We entered zero (no cushion) on Worksheet 8-D.
Shot Size
(PPC62)
This word determines the length of molten plastic drawn during the
plastication profile. Use this value to determine segment length in
End-of-segment Positions, above. Units are inches or millimeters. The
QDC uses this length for computing the end-of-plastication position (100%
shot size).
100% shot size = shot size + cushion
= PPC62 + PPC61
Enter a typical shot size for your machine on Worksheet 8-D.
The valve spanning procedures in chapter 9 require these initial cushion
and shot size values. Where required, we help you select correct final
values for your application in chapter 10. For additional information, refer
to Plastic Molding Module Reference Manual (publication 1771-6.5.88).
After you determine initial values and enter them on Worksheet 8-D, you
are ready to proceed.
1. Enter all worksheet values into your PLC-5 data table.
Important: Be sure that you have not altered any setpoints, and that you
have entered each and every setpoint exactly as on the worksheet.
2. Use the procedure described in chapter 4 to download command
blocks to the QDC module. We repeat the PPC block download data.
Block Block ID Command Bit Companion
PPC 15 B21/14 none
3. Check SYS61 and SYS62 for programming errors. Correct as
needed.
Enter and Download your
Worksheet Values