Drive Transfer Percent

Default: 0
Range: -500 to 500

This parameter affects the integral drive at the point when an axis transitions from position control to pressure control. The drive at that point is multiplied by this parameter and divided by 100, and this value is placed into the integral drive. The effect is that some controlled portion of the drive is carried forward from position control into pressure control.

Note: If this term is non-zero, then it is important that the Integral Gain also be non-zero. Otherwise, the initial integral drive will never return to zero and the pressure may never reach the requested pressure.

Why Bother?

There are two reasons for using this parameter to control pressure. First, a negative value can be entered to apply extra braking power at the time pressure mode is entered. This is desired in applications where momentum tends to cause the pressure to pass its command value even though no additional drive is applied. By applying negative drive, the momentum can be taken away.

Second, some users desire a bumpless transfer. A bumpless transfer is one in which the drive is kept the same on the transition from position to pressure control and therefore the mass being moved does not jerk on the transition. To achieve this affect, one would use a value in Drive Transfer Percent near 100.

TIP: In many applications the same effect of a bumpless transfer can be obtained with better results by using appropriate Extend and Retract Feed Forward values.