Maguire Products WEIGH SCALE BLENDER WSBMB Series, Installation Operation & Maintenance

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M A G U I R E P R O D U C T S , I N C .
87
W E I G H S C A L E B L E N D E R
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_MI Set AUTOMATICALLY by the CALIBRATE routine and also reset 10 cycles after
every power up
_MI numbers are set to 80 percent of the amount of material, in grams, that can feed
in one second based on normal valid dispense rates. A valid rate is considered the
normal dispense rate that occurs under normal conditions with equipment functioning
properly. When a rate lower than 80 percent of this actually occurs, it is assumed
that an equipment malfunction or loss of material has occurred. Under these
circumstances, normal rate correction routines are bypassed.
EXAMPLE: For a 1/2" auger feeder with a 60 RPM motor drive, the normal
metering rate is about one gram per revolution or 1 gram per second. Since the _MI
number is expressed as tenths of grams, 80 % of this is expressed as: (_MI 00008)
It is safe to use a _MI number that is too low but NOT safe to use
a number too high. Error correction routines will not work when
this number is too high.
Power-up always resets _MI to 00001. After 10 cycles have occurred without retries,
software will enter a corrected number. An exception to this is when the _AL (Alarm)
parameter is set to 0, the MI parameter is left unchanged. RATE CALIBRATION also
sets the _MI parameter.
_NC
Changes itself automatically over time
_NC is the allowable GRAM error within which NO flow rate corrections are made by
the software. Gram weight errors that are equal to, or less than, this number will be
accepted and no error corrections will take place. Since no equipment is perfect, we
must accept that a certain range of error is normal. To make corrections within this
range only adds an additional error due to hunting, and broadens the error range.
This parameter is adjusted automatically by the software according to the 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 increments of 1 or 1/10 gram and occur only 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 on
your unit.
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.