Understanding Oscilloscope Functions
TDS1000/2000-Series Digital Oscilloscope User Manual
17
Acquiring Signals
When you acquire a signal, the oscilloscope converts it into a digital
form and displays a waveform. The acquisition mode defines how
the signal is digitized and the time base setting affects the time span
and level of detail in the acquisition.
Acquisition Modes
There are three acquisition modes: Sample, Peak Detect, and
Average.
Sample. In this acquisition mode, the oscilloscope samples the signal
in evenly spaced intervals t o construct the wave form. This mode
accurately represents signals most of the time.
However, this mode does not acquire rapid 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 missed. In
these cases, you should use the Peak Detect mode to acquire data.
Peak Detect. In this acquisition mode, the oscilloscope finds 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 acquire and 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, averages them, and displays the resulting waveform. You
can use this mode to reduce random noise.