3 VMA Mode
3.1 Digital Demod Measurement
Sets the second window data to Search Time
Time
Time is the envelope of the data which is used to demodulation. It’s 20 % longer
than the Meas Interval, 10 % of the Meas Interval before the demodulated segment
and 10 % after.
Example
:DISP:DDEM:WIND2:DATA TIME
Sets the second window data to Time
Spectrum
Spectrum shows the FFT of the Raw Main Time waveform.
Example
:DISP:DDEM:WIND3:DATA SPEC
Sets the third window data to Spectrum
Demod
Displays the general demodulation results.
IQ Meas Time
Available for all modulation formats except 2-FSK.
IQ Meas Time is the measured time data results for the input signal. There are 6
available formats for this trace data: I-Q, Constellation, Real, Imaginary, I-Eye, Q-
Eye and Group Delay. 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
Group Delay Shows the derivative of phase response with respect to time
215 Vector Modulation Analyzer Mode User's &Programmer's Reference