MAGUIRE WEIGH SCALE BLENDER Installation Operation & Maintenance page 77

B L E N D E R 
W E I G H S C A L E
actual conditions of the metering.
This number has been set based on our experience with the dispense devices. If, over
time, the computer finds that the number is too large or too small, it will automatically adjust
it to match the actual conditions that exist with your equipment. These adjustments occur
in small increments once every 20 cycles. A change is made only if needed. Checking this
number from time to time will indicate the normal error range that is occurring with each
dispense device.
If you manually set this number to a very high value, you will effectively eliminate all error
correction attempts for the component. Gradually, over several months, the software will
adjust this number back down. If you wish to defeat a component's error correction
routines permanently, you may set NC to (_NC 29999). The software recognizes this
number as special and will not change it. This high setting eliminates error correction
attempts for this component. The component is still weighed, and retries still occur if short,
but the timing of each dispense is based only on previously learned rates and never
adjusted from new experience. A very small dispense in a high vibration environment may
actually be more consistently accurate if no adjusting occurs.
_RP and _RD (probably no need to ever change this)
RRP
_RD is reset AUTOMATICALLY shortly after POWER ON
NRP
CRP
These two parameters determine the dispense shortage error that is be acceptable for
ARP
each component.
_RP is the shortage expressed as a PERCENT of the target dispense weight and _RD is
RRD
the shortage expressed in GRAMS. These parameters are used together, either one will
NRD
force a "retry".
CRD
A "retry" is an additional dispense that is calculated to add the amount of material that is
ARD
short. This comes into play only when the amount dispensed is less than expected.
Retries will occur until the difference between the required amount and the metered
amount is equal to, or less than, the _RP percent difference AND the _RD weight
difference.
These numbers dictate just how close to perfect the dispense has to be before going on. If
the dispense overshoots the target, then the process continues. These parameters only
control the degree of weight SHORTAGE that is acceptable.
The _RP parameter is important when SMALL DISPENSE requests for color or additive
are made. Large PERCENT errors are more likely to occur when very small dispenses are
requested.
The _RD parameter is important when LARGE DISPENSE requests for color or additive
are made. Large GRAM weight errors are more likely to occur when very large dispense
percentages are being requested.
Depending on the accuracy of the metering device, a certain amount of hunting is to be
expected from one dispense to the next. Allowing the software to stop trying when it gets
sufficiently close to the target results in more perfect average dispenses. The mix chamber
and the barrel of your process machine average out the small errors that occur from cycle
to cycle.
If no shortage is ever to be allowed, setting _RP to 00000 will prevent any shortage from
occurring. This will, however, cause an overall average error on the plus side.
M A G U I R E P R O D U C T S , I N C .
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