Stanford Research Systems SR780, Operating Manual And Programming Reference

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4-60 Noise Source Menu
SR780 Network Signal Analyzer
Burst
Set the Burst Percentage of the noise [0.1%..100%].
In FFT group, the noise waveform is output for a percentage of the FFT time record of
the display selected as the Source Display.
In Octave group, the burst period is not linked to a display but is specified in time by the
Source Period.
For a continuous output, use 100% burst.
Triggering
When the burst percentage is less than 100%, the burst noise source is triggered by
External triggers. Set the Trigd Source Mode to trigger once (1-Shot) or with every
trigger (Continuous). In the 1-Shot case, the burst source only triggers on the first trigger
after [Start/Reset]. This same trigger starts the measurement (and waterfall). In the
Continuous case, the source triggers on every trigger, with a minimum trigger period set
by the time record of the Source Display (FFT) or the Source Period (Octave).
Source trigger outputs a noise burst every source period or FFT time record. The FFT
time records are synchronized to the burst.
Free Run Trigger Mode outputs a noise burst every source period.
Do not use Ch1 or Ch2 input trigger since the output will not start until a trigger is
received.
Command: NBUR (?) {x}
Source Display
Select the Source Display [DisplayA, DisplayB]. The Source Display only applies for the
FFT Measurement Group. The Source Display is the display which determines the burst
time record (FFT time record) and the bandwidth for bandlimited noise and chirp (FFT
Span). There is a single Source Display for both Chirp and Noise outputs. Changing this
entry for one type of source also changes it for the other.
Select which display sets the bandwidth for bandlimited noise. Burst Noise is a
percentage of the Source Display FFT time record length.
The noise output is continuous for Octave Analysis.
Command: CSRC (?) {i}
Source Period
Set the Burst Period for noise in Octave group [4 ms..1ks].