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MCTC manual
System performance
3.5.1
General
System performance can be characterized by the time it takes the component to reach the desired set point,
the accuracy of the set point 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 set point 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 accurate and regular. The accuracy and regularity of material output drops with
increased granule size. However this is only a problem with extreme low outputs.
3.5.2
MCBalance, MCPowder, MCHigh Output and MCLiquid
Periodical cleaning of the dosing 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 dosing algorithm needs a certain time to weigh material loss and adjust the RPM accordingly. This time
depends largely on the set point and the above mentioned two variables. The system constantly adjusts itself
to reach the best possible accuracy for current conditions. Over time it can reach an accuracy within
1% of
the set point
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 set point
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.
An unstable relay or tacho 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.
Reset regulation
•
Changing one parameter during production will cause the MCTC 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 MCTC 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.
