TDS 620A, 640A & 644A User Manual
3Ć3
Acquisition Modes
The acquisition system has several options for converting analog data into
digital form. The Acquisition menu lets you determine the acquisition mode
and how to start and stop acquisitions.
The digitizing oscilloscope supports three acquisition modes.
H Sample
H Envelope
H Average
Sample mode operates in realĆtime on a single trigger event, provided the
digitizing oscilloscope can acquire enough samples for each trigger event.
Envelope and average modes operate on multiple acquisitions. The digitizĆ
ing oscilloscope averages or envelopes several waveforms on a pointĆbyĆ
point basis.
Figure 3Ć1 illustrates the different modes and lists the benefits of each. It will
help you select the appropriate mode for your application.
Sample Mode
In Sample mode, the oscilloscope creates a record point by saving the first
sample (of perhaps many) during each acquisition interval. (An acquisition
interval is the time covered by the waveform record divided by the record
length.) This is the default mode.
Description of Modes