Rockwell Automation 1771-QDC, D17716.5.85(Passport) MNL. PLASTIC MOLDING MODULE - Manual (Page 122)

Span Your Valves
Chapter 9
9-5
Important: If downloading from your programming terminal, you must
download INC first, followed by IPC (chapter 4).
To download: Set:
INC B21/7
IPC B21/8
Test Valve Linearity with a Pressure vs. Time Injection Profile
1. Confirm that your pressure setpoints are equal to one-half system
pressure in IPC10, 14, 18, 22, 26, 30, 34, 38, 42, 46, and 50
(N44:66, 70, 74, 78, 82, 86, 90, 94, 98, 102, 106).
If not, correct them and download them to the QDC module. For
instructions, refer to chapter 4.
2. Check that the ram (screw) is still at the mold-end position.
3. Run a pressure vs. time injection profile by toggling DYC02-B04
(B35/404) from 0 to 1 to 0. The ram (screw) remains fixed so it can
exert pressure against the nozzle tip. If you observe no pressure,
verify that:
- no ram (screw) overtravel alarms are set. The QDC module
inhibits injection profiles if alarm bits SYS07-B00 through
SYS07-B05 are set.
- no programming error codes exist in SYS61 and SYS62.
4. The QDC module automatically runs injection, pack, and hold
profiles in succession. At completion, observe the pressures reported
for the middle segments in IPS22, 26, 30, and 34 (N44:614, 618, 622,
and 626). If the observed pressures are not within 20% of the
setpoints entered in IPC22, 26, 30, and 34, then check:
- Was your valve and solenoid alignment for the injection profile
the same as for direct-output ram (screw) action in the previous
section? If not the same, correct and repeat steps 3 and 4.
5. If the observed pressures IPS22, 26, 30, and 34 are still not within
20% of IPC22, 26, 30, and 34, your pressure valve is not linear over
the desired range. Correct for a non-linear valve as follows:
If actuals are at least 20%: And Your Selected
Valve is:
Then change INC44 (N44:40) as
follows:
Less than setpoints Direct Acting Increase in 5% steps
Reverse Acting Decrease in 5% steps
Greater than setpoints Direct Acting Decrease in 5% steps
Reverse Acting Increase in 5% steps