3 Short-Range Comms & IoT Mode
3.2 Modulation Analysis Measurement
:DISP:EVM:WIND:FORM CONS
selects Constellation as the first window data format
FSK Ref Time
Available only when the demodulation format is 2-FSK.
FSK Ref Time is the reconstructed ideal time waveform to compare FSK Meas Time
against. There are 6 available formats for this trace data: I-Q, Constellation, Real,
Imaginary, I-Eye and Q-Eye. Normally this trace data is displayed with I-Q format.
Format name Description
I-Q Real part of data is shown on horizontal axis, imaginary part is shown on vertical axis, Independent
variable (X axis) is normal to display
Constellation Same as I-Q, but for data with symbols defined, only the symbol points are shown as dots with no
connecting lines
Real (I) Real part of data is shown on a linear Y axis
Imaginary (Q) Imaginary part of data is shown on linear Y axis
I-Eye Real part of data is shown with X axis segmented (generally into 2 symbol segments) and each segment
is overlaid to show signal crossings at symbol boundaries
Q-Eye Same as I-eye but imaginary part of data is shown
Example
:DISP:EVM:WIND:DATA RTIM
sets the first window data to FSK Ref Time
:DISP:EVM:WIND:FORM CONS
selects Constellation as the first window data format
FSK Meas Spectrum
Available only when the demodulation format is 2-FSK.
FSK Meas Spectrum is the frequency spectrum of the FSK Meas Time trace data.
The demodulator produces the spectrum by windowing and FFT the FSK measured
data. If the measured filter is selected, the spectrum represents the signal after
filtering.
Example
:DISP:EVM:WIND:DATA MSPE
sets the first window data to FSK Meas Spectrum
FSK Ref Spectrum
Available only when the demodulation format is 2-FSK.
194 Short Range Comms & IoT Mode User's &Programmer's Reference
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