Campbell Scientific CR9000X Measurement and Control System - Manual (Page 207)

Section 6. Data Table Declarations and Output Processing Instructions
The value of each element (bin) of the histogram can be either the actual
number of times the signal crossed the level associated with that bin, or it can
be the fraction of the total number of crossings counted that were associated
with that bin (i.e., number of counts in the bin divided by total number of
counts in all bins).
Output: If the number of Level Crossing values equals L (NumLevels = L),
and the number of secondary ranges equals R (SecondDim = R), then the total
number of bins would be the product of L and R. The output is arranged
sequentially in the order [Bin(1,1), Bin(1,2), … Bin(1,R), Bin(2,1), Bin(2,2),
Bin(2,3), … Bin(L,1), Bin(L,2) …. Bin(L,R) ]. Shown in a two dimensional
array, the output would look like:
2nd Dimensional Values
Bin(1,1), Bin(1,2) . . . . . . . Bin(1,R)
Bin(2,1), Bin(2,2) . . . . . . . Bin(2,R)
Level
· · . . . . . . .
·
Crossing
·
. . . . . . .
·
Values
·
. . . . . . .
·
Bin(L,1), Bin(L,2) . . . . . . . Bin(L,R)
0
0.5
1
1.5
2
2.5
3
3.5
0 1 2 3 4 5 6
Sample Number
Signal Level
FIGURE 6.4-1. Example Crossing Data
One Dim Level Crossing Example: As an example of the level crossing
algorithm, assume we have a one dimension 3 bin level crossing histogram (the
second dimension =1) and are counting crossings on the rising edge. The
crossing levels are 1, 1.5, and 3. Figure 6.4-1 shows some example data.
Going through the data point by point :
Point
Source
Action Bin 1
(level=1) Bin 2
(level=1.5) Bin 3
(level=3)
1 0.5 First value, no counts 0 0 0
2 1.2 Signal crossed 1, 1 count to bin 1 1 0 0
3 1.4 No levels crossed, no counts 1 0 0
4 0.3 Falling level crossing, no counts 1 0 0
5 3.3 Add one count to first, second, and third
bins, the signal crossed 1, 1.5 and 3. 2 1 1
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