Delta RMC101 - Manual (Page 245)

Position/Pressure Control 4.12
Controller Features 4-59
o
The overshoot disappeared because the pressure did not change as quickly. There is some
lag upon the transition, but can likely be corrected by adjusting the entering speed.
• Another method of eliminating the lag immediately after the transition is to use the following two
parameters:
o
Integrator Preload
o
Drive Transfer Percent
Both of these parameters add drive to the Integral Drive when pressure control begins. The
difference between these two is that Integrator Preload adds a set value to the drive, while Drive
Transfer Percent adds a percentage of the drive immediately prior to the transition.
• The Drive Transfer Percent is useful when the entering conditions vary, such as the speed. The
Integral Preload is useful when the entering conditions are the same every time.
Warning! These parameters add drive to the Integral Drive. In order for this drive to "unwind" (go
towards zero), the Integral Gain must be greater than zero! If the Integral Drive cannot unwind,
the system will not control properly.
• Setting the Integral Preload to 200 (200 mV of drive), issuing a P cmd, and then running Event
Step 1 results in the following plot: