Spectrum Analyzer Module
In LabOne Releases prior to 17.12, the Spectrum Analyzer Module allows access to the functionality available in the Spectrum Analyzer Tab of the LabOne User Interface from an API. It’s a measurement tool that performs Fast Fourier Transforms (FFT) on demodulator output.
Future Deprecation Warning
In LabOne Release 17.12 and subsequent releases the Spectrum Analyzer (zoomFFT) Module has been superceded by the Data Acquisition Module. We strongly recommend using the Data Acquisition Module instead of the Recorder Module for frequency (and time) domain data acquisition. In particular, existing users of the Recorder module can use the guide Migrating a zoomFFT program to the DAQ Module. 
To get started please refer to the Spectrum Analyzer Tab in the relevant instrumentspecific User Manual. An example is available in the each of the LabVIEW, Matlab, Python or .NET APIs.
See Table 1 for the input parameters to configure the Spectrum Module and Table 2 for a description of the Spectrum Module outputs.
Setting/Path  Type  Unit  Description 


string 
 
The device ID that is being used for the measurement; the demodulator data is taken from this device. For example, 

bool 
 
When enabled, shifts the frequencies in the output grid so that the center frequency corresponds to the demodulation frequency. If not enabled, the center frequency is 0 Hz. 

uint64 
 
Number of lines of the FFT spectrum (powers of 2). A higher value increases the frequency resolution of the spectrum. 

bool 
 
Enable Endless mode; Run the FFT spectrum analysis continuously. 

uint64 
 
The number of FFTs to perform if not running in Endless mode. 

uint64 
 
Select the source signal for the FFT.


double 
 
Overlap of the demodulator data used for the FFT. Use 0 for no overlap and 0.99 for maximal overlap. 

double 
TC 
Minimum wait time in factors of the demodulator time constant (TC) before starting the measurement. The maximum of this value and 

double 
s 
Minimum wait time in seconds before starting the measurement. The maximum of this value and 

uint64 
 
The type of FFT window to use. 
Name  Type  Unit  Description 


double 
VoltsRMS 
The real part, x, of the complex FFT result. 

double 
VoltsRMS 
The imaginary part, y, of the complex FFT result. 

double 
VoltsRMS 
The absolute value, R=Abs(X+iY), of the complex FFT result. 

uint64 
Ticks 
Demodulator timestamp of the measurement (divide by the device’s clockbase to obtain seconds). 

double 
Hz 
The center frequency (corresponds to the demodulation frequency) of the spectrum. 

double 
1/s 
Sampling rate of the demodulator. 

double 
 
The absolute values of the demodulator’s lowpass filter transfer function for each grid point. The FFT result, x, y or R, may be divided by this value to obtain a filter compensated spectrum. 

double 
Hz 
The noiseequivalent power bandwidth of the demodulator 

double 
Hz 
The frequency grid. 

double 
 
The normalized equivalent noise bandwidth. If calculating spectral densities multiply your spectrum by this value to correct for windowing effects. 

double 
Hz 
FFT resolution: Spectral resolution defined by the reciprocal acquisition time (sampling rate/number of samples recorded). 

double 
dB 
The damping of the demodulator present at the border of the spectrum. 