How are the Target Preact parameters used on my HI 3010?

The Target Preact menu item is used to correct the amount of material that continues to flow after the Stop Command. When you fill a bag and the material continues to flow, this is called "in flight material" and causes overfill situations.  You want the process to stop earlier and deliver the correct amount of material without over filling. The Preact setting will achieve that goal. If the amount of overfill is always the same, then adjusting the setting in Preact is all that is needed. That setting will stop the fill or dispense early by that amount.  A setting of 4 would stop the fill or dispense 4 engineering units prior to the target set point.

If the material changes slightly, Smart Preact will help you keep those tight control requirements. The Smart Preact will monitor the over and under target amounts and automatically correct at the rate of one half the difference over several delivery cycles.   This prevents over corrections for an occasional accidental disruptions.

Start with a Preact setting of 0.5 percent of the expected delivery and let Smart Preact make the corrections.  This correction algorithm is not changeable.

To keep the corrections to a minimum, make sure the feeder is mechanically delivering consistently, keep the motion tolerance, averages, and WAVERSAVER parameters set low, and keep the target windows tight. If you are consistently under delivering, a tighter Target Minimum - under Target Window parameter can help. Verify the motion tolerance is tight so as to report the actual weight delivered.  Some feeders will dribble out the last few tenth over a few seconds, enough to slide under the motion tolerance, but enough to invalidate the delivery.  Also, verify the feeder cut-off is good.  Motion tolerance setting is normally the total load cell capacity times 0.0003.  This may add a few tenth of a second to the fill, but there needs to be a balance between accurate, consistent, and fast deliveries.