Hardy HI 1769-FC - Manual (Page 40)

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Chapter 4
0 = Pounds (lb) - Default
1 = Ounces (oz)
2 = Ton (ton) short ton
3 = Kilograms (kg)
4 = Grams (g)
5 = Metric Tonnes (t) long ton
Range: LB, OZ, TON, KG, G, T (default LB)
Any weight value input to the module (e.g. CALLOWWEIGHT, SPANWEIGHT) are in
the currently selected unit. The unit of measure can be set at any time, not just at
calibration. Set the metric before calibrating to verify the unit of measure.
Note The feeder control module does not need to be recalibrated after changing the metric
value.
Parameter 3 Span Weight
The Span Weight is a reference point derived from an actual measured weight. This
should not be confused with the Scale Capacity. If you have a 100 pound weight and you
place it on the scale, the Span Weight would be 100 pounds.
Parameter 4 Cal low weight
This reference weight is the weight of any product on the scale that is not removed during
calibration (derived from actual measured weight used at cal low or C2 cal). Normally,
you would remove all “live load” weight from the scale to obtain a CalLow Weight of
0.0. The location of the decimal point in this value is based on the Weight decimal point
parameter.
Range: Must be > or = 0.
Parameter 5 ROC time base
The Time Base is the length of time in seconds between two weight readings that are
subtracted to determine the initial flow rate. By increasing the time base, you increase the
time between weight readings. This allows more material to be dispensed during the time
base period. Low flow rates require a longer time base than high flow rates. The
controller measures weight to about 1 part in 10,000. The formula below provides a
minimum.
TIME BASE > (SCALE CAPACITY/5000)/LOW SETPOINT (units per sec.)
SCALE CAPACITY/10,000 = determines minimum weight increment
Example: (880/10,000) = 0.088 lb
The lowest setpoint in units per second @ 3 lb per min is: 3 lb/60 sec = 0.05 lb/sec
Thus:
TIME BASE = 0.088/0.05
TIME BASE = 1.76 (rounded to 2)
MINIMUM TIME BASE = 2 seconds
Range: In seconds, 0 decimal places. 1-1800 seconds.
Parameter 6 ROC time units
The units of time (seconds, minutes or hours) you want for the Rate of Change. The ROC
display on the summary display will read in these units.
Range: 0=sec, 1=min, 2=hr (default Seconds)