12-4
IM DL850E-01EN
FFT Analysis with User-Defined Computation (Optional)
You can analyze the following types of spectrums on models with user-defined computation (/G2 option).
Linear spectrums, power spectrum densities, cross spectrums, transfer functions, and coherence functions
Turning FFT 1 and FFT 2 On and Off (Display)
Set whether to perform FFT analysis. If you set this to ON, the FFT windows appear. You can display separate
FFT analysis results in the FFT 1 and FFT 2 windows.
• ON: FFT analysis is performed.
• OFF: FFT analysis is not performed.
FFT Settings (FFT Setup)
Set the spectrum type, the window function, and the type of averaging.
Spectrum Type (Type/Sub Type)
Set the spectrum type.
Type
Sub Type
Description
LS
MAG
Magnitude of the specified waveform’s linear spectrum
LS
LOGMAG
Logarithmic magnitude of the specified waveform’s linear spectrum
LS
PHASE
Phase of the specified waveform’s linear spectrum
LS
REAL
Real part of the specified waveform’s linear spectrum
LS
IMAG
Imaginary part of the specified waveform’s linear spectrum
RS
MAG
Magnitude of the specified waveform’s RMS spectrum
RS
LOGMAG
Logarithmic magnitude of the specified waveform’s RMS spectrum
PS
MAG
Magnitude of the specified waveform’s power spectrum
PS
LOGMAG
Logarithmic magnitude of the specified waveform’s power spectrum
PSD
MAG
Magnitude of the specified waveform’s power spectrum density
PSD
LOGMAG
Logarithmic magnitude of the specified waveform’s power spectrum
density
CS
MAG
Magnitude of the cross spectrum of the specified two waveforms
CS
LOGMAG
Logarithmic magnitude of the cross spectrum of the specified two
waveforms
CS
PHASE
Phase of the cross spectrum of the specified two waveforms
CS
REAL
Real part of the cross spectrum of the specified two waveforms
CS
IMAG
Imaginary part of the cross spectrum of the specified two waveforms
TF
MAG
Magnitude of the transfer function of the specified two waveforms
TF
LOGMAG
Logarithmic magnitude of the transfer function of the specified two
waveforms
TF
PHASE
Phase of the transfer function of the specified two waveforms
TF
REAL
Real part of the transfer function of the specified two waveforms
TF
IMAG
Imaginary part of the transfer function of the specified two waveforms
CH
MAG
Magnitude of the coherence function of the specified two waveforms
Analysis Source Waveforms (Source1 and Source2)
1
Set the analysis source waveform to one of the waveforms below.
CH1 to CH16,
2
16chVOLT,
3
16chTEMP/VOLT,
3
CAN,
4
LIN,
4
Math1 to Math6
5
1 You can set Trace2 when Type is set to CS, TF, or CH.
2 You can select the channel of an installed module. However, you cannot select the channel of a logic module.
3 When a 16-CH voltage input module or 16-CH temperature/voltage input module is installed. After you select
16chVOLT or 16chTEMP/VOLT, select a sub channel.
4 On the DL850EV when a CAN bus monitor module or CAN & LIN bus monitor module is installed. After you
select CAN or LIN, select a sub channel. You cannot select waveforms whose data type (Value Type) is set to
Logic.
5 You cannot select Math7 or Math8.
When analysis is performed on a linearly scaled channel, the scaled values are used.
12 FFT