Analyzing Wavef
orms
6. View time-domain and frequency-domain
waveforms simultaneously.
Use Gating to s
elect only a part of
the time-domain waveform for spectral
analysis. (See page 118, Gating.)
Quick Tips
Sources for spectral math waveforms must be channel or other math waveforms.
Use short record lengths for faster instrument response.
Use long record lengths to lower the noise relative to the signal and increase the frequency resolution.
Different window functions produce different filter response shapes in the spectrum and result in different resolution
bandwidths. See the online help for more information.
The resolution bandwidth (RBW) directly controls the gate w idth. Therefore, the time domain gate markers move
as you adjust the control.
You can display the linear magnitude of the real data or the imaginary data in the spectrum. This is useful if you process
the spectrum off line and transform it back into a time domain trace.
Using Mask Testing
Serial Communications Mask Testing (Option MTM or MTH) allows you to compare your signal to a predefined template
or mask. For the signal to pass the test, it must fall outside the segments defined by the mask. Generally, standards
commi
ttees such as ANSI defi ne the masks. To perform mask testing do the following:
1. Select Mask > Source....
MSO70000/C, DPO/DSA70000B/C, DPO7000, and MSO/DP O5000 Series U ser M anual 131