Tektronix TDS5000B Series, Online Help Manual

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Acquiring and displaying a noisy square wave signal illustrates the difference between the modes.
Note how Envelope mode reduces the noise while Average mode captures its extremes:
In Waveform Database mode, the instrument acquires and displays a waveform that is the
accumulation of several acquisitions. In addition to time and amplitude, the waveform displays a
count of the number of times a specific sample point has been acquired. The value at each point on
the waveform is a counter that reflects the hit intensity. The instrument acquires data after each
trigger event using Sample mode. It then determines the location of each sample point and
accumulates it with shared data from previous acquisitions. This is the only mode that can be used
when doing mask testing with an optical standard. Fast Acq is inhibited in Waveform Database
mode.
Fast Acquisitions
To Use
Click the button under Fast Acquisitions to turn Fast Acquisitions mode on and off; this has the
same effect as pushing the front-panel FastAcq button.
Behavior
Fast Acquisitions mode keeps the dead time between acquisitions very short. This improves the
chances of acquiring infrequent events. When Fast Acquisitions are turned on, the front-panel
FastAcq button is lighted.
If Fast Acquisitions mode is on and you attempt to activate a feature that conflicts with this mode,
Fast Acquisitions mode will be inhibited. When the conflicting feature is turned off, in most cases,
Fast Acquisitions will resume. The following bullet items describe some interactions:
ƒ Measurements are supported in Fast Acquisitions mode when you display one or two
channels. If you display three or more channels, Fast Acquisitions mode is turned off, and the
measurements are displayed. Fast Acquisitions mode is automatically enabled when you
switch back to displaying one or two channels.
ƒ Histograms are supported in Fast Acquisitions mode when you display one or two channels. If
you display three or more channels, Fast Acquisitions mode is turned off, and the histograms
are displayed. Fast Acquisition mode is automatically enabled when you switch back to
displaying one or two channels.
ƒ Deskew is supported in Fast Acquisitions mode when you acquire one or two channels. If you
acquire three or more channels, Fast Acquisition mode is turned off and the message, Deskew
not applied in FastAcq when three or more channels are acquired, is displayed. When you
switch back to acquiring one or two channels, the message, Deskew is re-enabled, is displayed
and deskew values are applied again.
Use the Horiz/Acq menu
Fast Acquisitions
selection to directly toggle this mode on or off.