The Full Span function will set the span to the
full frequency range.
This function will set the start and stop
frequencies to 0Hz and 3GHz respectively.
The Zero Span function will set the frequency
range of the sweep to 0Hz and fixes the start
and stop frequencies to the center frequency.
The Zero Span function measures the time
domain characteristics of the input signal at the
center frequency. The horizontal axis is
displayed in the time domain.