Rockwell Automation 1440-SDM02-01RA XM-124 Standard Dynamic Measurement Module - Manuel (Page 148)

148 Rockwell Automation Publication 1440-UM001C-EN-P - May 2014
Appendix B CIP Objects
If the data format is Magnitude Data then the Normalized Value Array is an
array of UINT (16-bit unsigned integers ranging from 0 to 65535). The number
of UINTs in the spectrum data array is equal to the Number of 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 -32,768…32,767). 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:
The Waveform Data structure contains an array of values that, taken together, are
the output of the sampling performed by the Spectrum/Waveform Measurement
Float Data
n
Amplitude Reference
Normalized Data
n
65536
-------------------------------------------- =
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
----------------------------------------
 
 
 
=