Rockwell Automation 1771-QDC, D17716.5.93(Passport) PLASTIC MOLDING MODULE - Manual (Page 226)

Span Your Valves
Chapter 9
9-60
3. Convert the min and max flows obtained from your flow curve to
ejector cylinder velocities. This is done by:
Ejector Cylinder Velocity (in/sec) =
Flow (in 3 /sec)
Area (in 2 )
- where area is the inside diameter of the cylinder. This area may
be different for the rod and piston ends of the cylinder:
Area for Rod End =
I.D. of cylinder
2
Rod diameter
2
π −
2 2
Area (no Rod) =
I.D. of cylinder
2
π
2
π
- The flow assumes no restrictions on the cylinder exhaust port .
4. Enter minimum velocities (usually 0) from the calculation into
EAC45, ERC45. Enter maximum velocities into EAC46, ERC46.
5. Divide the voltage/current corresponding to minimum velocities by
the full range of valve input signal to determine the percent signal
output for minimum. Enter these values into EAC47 and ERC47.
6. Divide the voltage/current corresponding to maximum velocities by
the full range of valve input signal to determine the percent signal
output for maximum. Enter these values into EAC48 and ERC48.
7. Download changes to the QDC module.
Important: If downloading from your programming terminal, download
EAC, ERC, and EPC in that order, with download bits B21/21, 22, and 23.
Test Valve Linearity with an Ejector Velocity Profile
1. Select velocity vs. position control for the ejector profile by setting
EPC03-B00 (B39/160) = 0.
2. Select velocity setpoints for ejector advance and ejector retract that
are typical of velocities you would run during normal machine
operation. Enter these setpoints into EPC09 and EPC33 (N45:125
and N45:149).
3. Download changes to the QDC module.
Important: If downloading from your programming terminal, download
EPC with download bit B21/23 (chapter 4).
4. Jog your ejector to the fully retracted position.