Rockwell Automation 1440-DYN02-01RJ XM Dynamic Measurement Module - Manuel (Page 141)

Publication ICM-UM002F-EN-E - March 2013 141
CIP Objects Appendix B
Spectrum Lines . To convert the normalized spectrum data into floating point
values, use the following equation:
Where Float Data n is the value for the nth spectrum bin, and 0
≤ n ≤ Number
of Spectrum Line .
The Float Data value represents an amplitude value if Data Format is real
data. The Float Data represents a power value if Data Format is power data.
If the data format is Complex Data then the Normalized Value Array is an
array of INT (16-bit signed integers ranging from -32768 to 32767). There are
two INTs (real and imaginary values) in the array for each spectrum bin (the
array size is twice the Number of Spectrum Lines). To convert the
normalized spectrum data into real and imaginary values, use the following
equations:
Where Real Data n and Imaginary Data n are the real and imaginary values
for the nth spectrum bin, and 0
≤ n ≤ Number of Spectrum Line.
The Real Data and Imaginary Data values are converted into magnitude and
phase values with the following equations:
Float Data
n
Amplitude Reference
Normalized Data
n
32768
-------------------------------------------- =
Real Data
n
Amplitude Reference
Normalized Data
2n
32768
----------------------------------------------- =
Imaginary Data
n
Amplitude Reference
Normalized Data
2n 1 +
( )
32768
------------------------------------------------------------- =
Magnitude Data
n
Real Data
n
2
Imaginary Data
n
2
+ =
Phase Data
n
arctan
Imaginary Data
n
Real Data
n
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