In dry systems, anticipation should be configured based on the specific system. In this example, the order amount is 1000 pounds, and the anticipation is set at 200 pounds. When the dispensed amount reaches 800 pounds, 200 pounds short of the order amount, the gate will shut, and bumping will begin until the order amount is reached. The ideal for a dry system is to have anticipation just under deliver by 1 or 2 bumps, then the system will bump the last bit of material out of the bin(s) to reach the requested amount.
Anticipation in dry systems estimates the material in freefall. In this example the system will close the gate at 800 pounds and expect 200 pounds will still be falling.
If too much product is delivered, anticipation should be increased since there is more product in freefall than expected.
If too little is dispensed, anticipation is greater than the freefall value and should be decreased.
Note: Anticipation Update Factor is not commonly recommended for use in dry facilities and should be set to "0" to disable updating. Refer to Liquid Panel settings for chem inject systems.
In dry hopper systems, additional anticipation settings exist. For bins that have 3 position gates, "Preact" can be used; “Preact”, short for “Pre-Anticipation” will close the gate to the trim position, limiting the material flow as it approaches the primary anticipation configuration and final request weight. This allows more material to reliably be dispensed without overshooting the goal. Generally the "Preact" should be about twice the anticipation, but adjust for the most consistency for your facility.
Once the anticipation target has been reached, the gates will close so material can finish falling momentarily, before the system switches to “bumping” to approach the final weight. Bumping, measured in 32nds or 1/32 of a second, repeatedly opens and closes the gates to dispense the final remaining quantity of material in a controlled manner.
“Open 32nds” causes the gate in question to actuate towards open for a specified time. Following this the gate will be triggered to close for the period specified in “Close 32nds”. The longer close time also allows the scale reading to settle so that the system may monitor progress.
To dial-in bump behavior, make Close 32nds the equivalent of 3-4 seconds, and then adjust Open 32nds by one or two 32nds at a time until it drops a consistent amount of material. If the scale is not settling between bumps try making Close 32nds longer. Once the Open 32nds value is found, adjust the Close 32nds slowly to allow the scale to mostly settle between bumps.
The Anticipation Multiplier is used to adjust the anticipation for having multiple bins activate at once. A value of 1.00 is default and means anticipation is multiplied by the number of bins. If needed, adjust this value by 0.01 at a time if in consistency is found when using multiple bins at a time.
In liquid systems anticipation tries to predict product in the line that will make it to the destination, and controls when the pump and valves need to be triggered to deliver the requested amount.
In liquid systems, the system can dial-in anticipation based on any error in dispensing. The anticipation update factor recommended value is "0.5". This anticipation update factor means that the anticipation will be updated by half ("0.5") the value of any error in dispensing a load, dialing-in the anticipation over just a few loads.
If too much product is delivered, anticipation should be increased since the valves triggered too late
If too little is dispensed, anticipation is too large and should be decreased to deliver more product.