Acquisition; Auto Setup - Teledyne HDO9000 Operator's Manual

HDO9000 High Definition Oscilloscopes Operator's Manual

Acquisition

The acquisition settings include everything required to produce a visible trace on screen and an
acquisition record that may be saved for later processing and analysis:
Vertical axis scale at which to show the input signal and probe characteristics that affect the
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signal, such as attenuation and deskew time
Horizontal axis scale at which to represent time, and acquisition sampling mode and sampling
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rate
Acquisition trigger
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Optional acquisition settings include bandwidth filters and pre-processing effects, vertical offset, and
horizontal trigger delay, all of which affect the appearance and position of the waveform trace.
The overall length of the acquisition in time is determined by the Time/Division (timebase) setting,
with acquisition time equal to 10 times the Time/Division setting. The formula for maximum sample
rate is: Sample Rate = Memory Samples/Acquisition Time, with the maximum sample rate being limited
by the instrument's analog-to-digital converter (ADC). The instrument allocates memory as needed to
maintain the highest sample rate possible for the timebase.
To avoid aliasing and other waveform distortions, it is advisable (per Nyquist) to acquire at a sample
rate at least twice the bandwidth of the input signal. It can be shown that a sample rate 10 times the
acquisition bandwidth is preferable in order to over sample fast signal rise times consistent with the
oscilloscope bandwidth.
Those with higher speed acquisition systems may need to manually adjust Bandwidth, Time/div,
Sample Rate, and the number of Active Channels to achieve the optimal result. Most Teledyne LeCroy
oscilloscopes have a Fixed Sample Rate option, which uses whatever memory is required for the
acquisition time, until none remains.

Auto Setup

Auto Setup quickly configures the essential acquisition settings based on the first input signal it
finds, starting with Channel 1. If nothing is connected to Channel 1, it searches Channel 2 and so forth
until it finds a signal. Vertical Scale (V/div), Offset, Timebase (Time/div), and Trigger are set to an
Edge trigger on the first, non-zero-level amplitude, with the entire waveform visible for at least 10
cycles over 10 horizontal divisions.
To run Auto Setup:
1. Either press the front panel Auto Setup button or choose Auto Setup from the Vertical,
Timebase, or Trigger menus. All these options perform the same function.
2. Press the Auto Setup button again or use the touch screen display to confirm Auto Setup.
After running Auto Setup, you'll see the words "Auto Setup" next to an Undo button at the far right of
the menu bar. This allows you to restore the settings in place prior to the Auto Setup.
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mechanism