Rockwell Automation 1771-QDC, D17716.5.86(Passport) PLASTIC MOLDING MODULE - Manual (Page 174)

Span Your Valves
Chapter 9
9-17
Test Valve Linearity with a Velocity Profile
1. Select velocity vs. position control for the entire clamp close
operation by resetting the following bits to zero:
CPC03-B00 (B37/288)
CPC03-B02 (B37/290)
CPC03-B04 (B37/292)
2. Download the CPC block to the QDC module.
Important: If downloading from your programming terminal, download
CPC by setting B21/6 (chapter 4).
3. Jog your clamp to the full open position.
4. Enable first clamp close by setting DYC02-B00 (B34/400) to 1. The
clamp should move from its start position through the first clamp
close and low pressure close profiles. If no motion, verify that:
- no overtravel alarms are set. The QDC module inhibits clamp
close if SYS07-B00 through -B05 are set
- no programming error codes exist in SYS61 and SYS62
5. Upon completion of clamp close, observe the velocity reported for 1st
clamp close segment 2 CPS12 (N43:664). This velocity should be
relatively close to the setpoint you entered in CPC12 (N43:248). If
the observed velocity is not within 25% of the setpoint, verify that:
- the values from your flow rate curves are correct
- your calculations are correct
If the observed velocity CPS12 is still not within 25% of CPC12, your
flow valve is not linear over the desired range of operation. Correct as
follows:
If: And Your Selected
Valve is:
Then change FCC48
(N43:44) as follows:
CPS12 was less than CPC12 Direct Acting Increase in 5% steps
Reverse Acting Decrease in 5% steps
CPS12 was more than
CPC12
Direct Acting Decrease in 5% steps
Reverse Acting Increase in 5% steps
To do this: change FCC48, download the FCC block, and repeat steps 3-5.
Repeat as necessary.
6. Copy final FCC48 (N43:44) into SCC48 and TCC48 (N43:104 and
164), and download these changes to the QDC module.