Utilising Deep Memory with Rigol DS1000 Oscilloscope

Oscilloscope memory determines how long an acquisition can remain while retaining useful time resolution. The original DS1000D/E instructions described a one-million-point record as deep memory. Current instruments may provide tens or hundreds of millions of points, but the underlying trade-off is unchanged: time span, sample rate, active channels and record length must be considered together.

Memory is valuable only when the oscilloscope can acquire, navigate, search and measure the resulting record efficiently.

The relationship that matters

For example, one million samples spread across 0.5 seconds gives an average interval of about 500 ns between samples, equivalent to roughly 2 MSa/s. A short edge can be missed or poorly represented even though the oscilloscope’s headline maximum sample rate is much higher.

A practical deep-memory workflow

• Set the total event duration that must be captured.
• Estimate the fastest edge or shortest pulse that must remain visible.
• Choose a record length and confirm the resulting sample rate on the instrument.
• Enable every channel required for the real test; channel count may affect available sample rate or memory.
• Capture once, then use zoom rather than changing the timebase and reacquiring a different event.
• Use search, protocol events or measurements to navigate instead of scrolling blindly.
• Export only the necessary record or segment and retain the oscilloscope setup with it.

When more memory genuinely helps

Common traps

• Assuming the maximum sample rate applies at every timebase and channel configuration.
• Increasing memory without checking acquisition, processing and save time.
• Trusting a visually smooth interpolated trace when there are too few real samples.
• Using peak-detect, averaging or high-resolution mode without understanding how it changes the stored data.
• Capturing a huge record without a trigger, search condition or navigation plan.

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