UnderstandingOscilloscope Functions
TDS1000/2000-Series Digital Oscilloscope User Manual 17
Acquiring SignalsWhen you acquire a signal,the oscilloscope converts it into a digi tal
form and displaysa waveform. The acquisition mode defineshow
the signal is digitizedand the time base setting affects the time span
and level of detail in the acquisition.
Acquisition Modes
There are three acquisitionmodes: Sample, Peak Detect, and
Average.
Sample. In this acquisitionmode, the oscilloscope samples the signal
in evenly spaced intervals to construct the waveform. This mode
accurately represents signalsmost of the time.
However, this mode does not acquire rapi d variations in the signal
that may occur between samples.This can result in aliasing
(described on page 20) and may cause narrow pulses to be m issed. In
these cases, you should use the Peak Detect mode to acquire data.
Peak Detect. In this acquisition mode, the oscilloscopefinds the
highest and lowest values of the input signal over each sample
interval and uses these values to display the waveform. In this way,
the oscilloscope can acquireand display narrow pulses, which may
have otherwise been missed in Sample mode . Noise will appear to be
higher in this mode.
Average. In this acquisition mode, the oscilloscope acquires several
waveforms, averagesthem, and displays the resulting waveform. You
can use this mode to reduce random noise.