Rockwell Automation 1771-QDC, D17716.5.86(Passport) PLASTIC MOLDING MODULE - Manual (Page 185)

Span Your Valves
Chapter 9
9-28
Test Valve Linearity with a Velocity vs. Position Profile
1. Change your velocity setpoints to one-half maximum velocity
(0.5 times the velocity in INC48) in these words:
IPC09, 13, 17, 21, 25, 29, 33, 37, 41, 45, and 49
(N44:65, 69, 73, 77, 81, 85, 89, 93, 97, 101, 105).
Important: Be sure the correct pump adders are set for this velocity.
2. Download the INC and IPC data blocks to the QDC module.
Important: If downloading from your programming terminal, download
INC followed by IPC (chapter 4).
To download Set B21/
INC 7
IPC 8
3. Run an open-loop velocity vs. position profile. Do this by toggling
DYC02-B04 (B34/404) from 0 to 1 to 0.
4. The QDC module automatically runs the injection, pack, and hold
profiles in succession. At completion, observe the actual segment
velocities reported by the QDC module in mid-profile segments 5, 6,
and 7 in IPS25, 29, and 33 (N44:617, 621, and 625).
If they are not within 20% of mid-profile velocity setpoints IPC25,
29, and 33, your flow valve is not linear over the desired range of
operation. Correct for a non-linear valve by adjusting as follows:
If observed velocity is 20%
or more:
And Your Selected
Valve is:
Then change INC47
(N44:43) as follows:
Below setpoints Direct Acting Increase in 5% steps
Reverse Acting Decrease in 5% steps
Above setpoints Direct Acting Decrease in 5% steps
Reverse Acting Increase in 5% steps
To do this: change INC47, download INC and IPC blocks, and repeat
steps 2-4. Repeat as necessary.