System Performance; Reset Regulation - Conair TrueFeed User Manual

8. System performance

System performance can be characterized by the time it takes the unit to reach the desired setpoint, the
accuracy of the setpoint and the regularity of the material output.
The algorithm is self-adjusting to the conditions and because the conditions vary, it cannot be predicted how
long it will take the unit to adjust itself and reach a setpoint with certain accuracy.
The following variables influence system performance:
Material properties. Easy flowing, non-sticky and non-static material that comes in the form of small
granules or powder can be dosed very accurately and consistently. The accuracy and consistency of
material output drops with increased granule size. However this is only a problem with extremely low
outputs.
Periodical cleaning of the feeding cylinder and seals is necessary for proper operation.
Extreme vibrations and shocks influence system performance noticeably. Normally the system will be
able to compensate for vibrations and shocks.
The Dual TrueFeed algorithm needs a certain time to weigh material loss and adjust the RPM accordingly. This
time depends largely on the setpoint and the above mentioned three variables. The system constantly adjusts
itself to reach the best possible accuracy for current conditions. Over time it can reach an accuracy within
1%. Under "normal" circumstances the unit will be more accurate than 10% after the first adjustment of the
RPM.
Before the unit makes its first RPM adjustment it might be running already very close to the desired setpoint
because it uses a cylinder and material reference system to determine the first RPM setting. This accuracy,
however, cannot be guaranteed because material properties can vary substantially from material to material.
With injection molding, the shot to shot accuracy depends, besides the variables mentioned so far, on the shot
time. If big and heavy granules have to be dosed in a very short time this will influence the shot accuracy and
repeatability because one granule can make a difference of a few percent to the shot weight.
An unstable relay signal has a negative effect on the accuracy, repeatability and speed of the system because
it will adjust to these parameter changes.
A long cycle time combined with low dosage per shot can result in a slow system.

8.1 Reset regulation

Changing one parameter during production will cause the balance to adjust to the changes but it will not
reset the regulation totally.
Changing more production parameters during production within 10 seconds after each other will cause
the TrueFeed's regulation to reset. This is necessary for the system to adjust quickly to these big
changes in the settings.
Switching the power OFF and ON again will also cause the regulation to reset.
Motor OFF and ON again will only cause the regulation to pause. The start-up RPM will be the same as
the last RPM before the stop.
Changing one parameter with motor OFF causes total reset of the regulation.
With auto start = ON (CONFIGURATION menu) the motor follows the last status (motor Standby or
motor Stop status) and causes total reset of the regulation.
35 Dual Feed TrueFeed Manual