Main Feature Description
DSO5000P Series Digital Storage Oscilloscope User Manual 11
4.3 Data Acquisition
When you acquire an analog signal, the oscilloscope will convert it into a digital one. There are
two kinds of acquisition: Real-time acquisition and Equivalent acquisition. The real-time acquisition
has three modes: Normal, Peak Detect, and Average. The acquisition rate is affected by the
setting of time base.
Normal: In this acquisition mode, the oscilloscope samples the signal in evenly spaced intervals to
establish the waveform. This mode accurately represents signals in most time. However, it does
not acquire rapid variations in the analog signal that may occur between two samples, which can
result in aliasing and may cause narrow pulses to be missed. In such cases, you should use the
Peak Detect mode to acquire data.
Peak Detect: In this acquisition mode, the oscilloscope gets the maximum and minimum 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 those narrow pulses that may have otherwise been
missed in Normal mode. However, 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.
Equivalent Acquisition: This kind of acquisition can be utilized for periodic signals. In case the
acquisition rate is too low when using the real-time acquisition, the oscilloscope will use a fixed
rate to acquire data with a stationary tiny delay after each acquisition of a frame of data. After
repeating this acquisition for N times, the oscilloscope will arrange the acquired N frames of data
by time to make up a new frame of data. Then the waveform can be recovered. The number of
times N is related to the equivalent acquisition rate.
Time Base: The oscilloscope digitizes waveforms by acquiring the value of an input signal at
discrete points. The time base helps to control how often the values are digitized. Use the
SEC/DIV knob to adjust the time base to a horizontal scale that suits your purpose.
4.4 Waveform Scaling and Positioning
The display of waveforms on the screen can be changed by adjusting their scale and position.
Once the scale changes, the waveform display will increase or decrease in size. Once the position
changes, the waveform will move up, down, right, or left.
The channel reference indicator (located on the left of the graticule) identifies each waveform on
the screen. It points to the ground level of the waveform record.
Vertical Scale and Position: The vertical position of a waveform can be changed by moving it up
and down on the screen. To compare data, you may align a waveform over another. When you
push the VOLTS/DIV button to change the vertical scale of a waveform, the waveform display will
contract or expand vertically to the ground level.
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