Reset Tone Phase On Burst

Controls: Gen Dlg >> Stream >> Tone Freq >> Burst
Macro: ToneRstBurst

If you toggle this control on and the Burst modulator is active, the main wave will be forced to the Phase setting at the start of each burst; every burst will be identical, even multiple bursts in a train. The phase is reset just prior to the Rise stage, but after the Lag stage, so Burst Lag doesn't affect the phase.

When Play Wave is in use with Burst modulation, this option resets the playback point to the Play From location at the start of each burst. If you are using Play Burst Single mode you should probably have either this option or the following Reset Burst On Train selected, unless you are also using Play Step mode. The reason is that in Play Interpolate or Round modes the samples don't necessarily line up with those in the file due to differences between the recorded sample rate and the current sample rate.

Note that in order to view the waveform so you can see the effects of this control, you need to have Train or Burst Sync active, along with Gen Sync and the main Trigger. Otherwise, the bursts will appear at various locations across the screen, depending upon the relative timing of the bursts versus the screen updates.

If neither this button nor the following Reset Phase on Train is active, the burst will start at whatever main wave phase is present at the instant the burst starts. Each burst will typically be different; if you sync to the burst, the main wave will appear to roll through it.

Why might you want ever-changing bursts? One reason is to uncover certain behaviors of the system under test. A typical example is where the response of the system contains two separate components: One responds to the instantaneous waveform, and the other responds only to the spectrum in a phase-insensitive manner. By varying the starting phase and averaging many responses, the contributions of the waveform portion will be minimized. (Alternatively, waveform Avg Add and Avg Sub may be used for a similar purpose. Sometimes, an even better way to do this is to average while alternating between two bursts with opposite polarities.)

Macro Notes:

L.1.ToneRstBurst=1 will cause the Left Stream 1 Tone Phase to be reset at the start of each burst. L.1.ToneRstBurst=0 cancels that, and L.1.ToneRstBurst=x toggles it on and off.

Macro Notes:

L.1.ToneRstTrain=1 will cause the Left Stream 1 Tone Phase to be reset at the start of each train. L.1.ToneRstTrain=0 cancels that, and L.1.ToneRstTrain=x toggles it on and off.

See also Reset Phase on Train, Reset Phase on Sweep, Burst Dialog, Tone Frequency Dialog, Waveform Stream Controls.