Campbell Scientific CR5000 Measurement and Control Module - Manual (Page 114)

Section 6. Data Table Declarations and Output Processing Instructions
6-20
Processes data with the Level Crossing counting algorithm. The output is a
two dimensional Level Crossing Histogram. One dimension is the levels
crossed; the second dimension, if used, is the value of a second input at the
time the crossings were detected.
The total number of bins output =
NumLevels*2ndDim. For a one dimensional level crossing histogram, enter 1 for
2ndDim.
The source value may be the result of a measurement or calculation. Each time
the data table with the Level Crossing instruction is called, the source is
checked to see if its value has changed from the previous value and if in any
change it has crossed any of the specified crossing levels. The instruction can
be programmed to count crossings on either the rising edge (source changes
from less than the level to greater than the level) or on the falling edge (source
changes from greater than the level to less than the level).
0
0.5
1
1.5
2
2.5
3
3.5
0 1 2 3 4 5 6
FIGURE 6.4-1. Example Crossing Data
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: