Red Lion LEGEND - Manual (Page 54)

Once the Number of Count Edges (NCE) to be used has been determined, the
Remaining Scaling factor required, “K R ”, can be calculated. This is the Total
Scaling Factor, “K T ”, divided by the Number of Count edges used as shown in
Formula #2:
FORMULA #2: K R = K T
¸ NCE
WHERE:
K R = Remaining Scaling Factor.
K
T
= Total Scaling Factor.
NCE = Number of Count Edges.
In our original example, the Total Scaling Factor, “K T ” was determined to be
0.041667. Since this value is less than one, sufficient pulse information is being
generated, i.e., there is enough resolution for the units selected. The Number of
Count edges can be left at the factory set value of X1. The Total Scaling Factor,
“K
T ”, therefore equals the Remaining Scaling Factor, “K R ”.
K R = 0.041667 ¸ 1 = 0.041667
If the remaining scaling is between 0.6000 and 5.9999, it can be programmed
directly into the Scale Factor value and the X1 factory setting for the Count Scale
Multiplier “SCM”, can be used.
COUNT SCALE MULTIPLIER
The general rule for choosing an SCM value is, when the Remaining Scaling
Factor, “K R ”, is less than 0.6000, an SCM value of 0.1 or 0.01 can be used to get a
Scale Factor value between 0.6 and 5.9999 or to the point where the maximum
number of significant digits is obtained.
FORMULA #3: SF = K R
¸ SCM
WHERE:
SF = Count Scale Factor.
K
R
= Remaining Scaling Factor.
SCM = Count Scale Multiplier.
Following our continuing example, it is easy to see that the Remaining Scaling
Factor, “K R ” (0.041667), cannot fit into the Scale Factor Value without losing
significant digits. Using the formula above and a Scale Multiplier value of 0.01
will allow us to get the maximum number of significant digits possible for the
Count Scale Factor value:
SF = K R
¸ SCM = 0.041667 ¸ 0.01 = 4.1667
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