1.6 ANTECEDENTES
1.6.7 Diagnóstico sectorial
1.6.9.14 Eje de desarrollo cultural
1.6.9.14.1 Costumbres
Acquisition Modes
Normal Mode
For the majority of use models and signals, Normal acquisition mode yields the best oscilloscope picture of the waveform.
The analog channels can have up to 2 million samples per channel for the 54620-series and up to 4 million samples per channel for the 54640-series behind the 1,000-pixel column oscilloscope display. Some compression of samples to display points is obviously necessary, but due to the high plot rate (up to 25 million vectors/second), the compression is much less that previous oscilloscopes. This means the signal will look “right” at many more operating points.
Peak Detect
Peak Detect is useful if you are interested in capturing a narrow event relative to the time window of interest. Using Peak Detect and infinite persistence together is a powerful way to find spurious signals and glitches.
54620-series Peak detect acquire mode displays any signal pulse wider than 5 ns, allowing you to find glitches and narrow spikes regardless of sweep speed. Because of MegaZoom memory, peak detect is only necessary at sweep speeds of 1 ms/div and slower. At faster sweep speeds, Normal acquire mode can capture the narrow peaks.
At sweep speeds slower than 1 ms/div, the oscilloscope can acquire more samples than can fit into MegaZoom memory. The oscilloscope selects samples to store such that no local minimum or maximum wider than 5 ns is missed. In peak detect mode, narrow glitches and sharp edges are displayed more brightly than when in Normal acquire mode, making them easier to see.
54640-series Peak detect acquire mode displays any signal pulse wider than 1 ns, allowing you to find glitches and narrow spikes regardless of sweep speed. Because of MegaZoom memory, peak detect is only necessary at sweep speeds of 500 µs/div and slower. At faster sweep speeds, Normal acquire mode can capture the narrow peaks.
At sweep speeds slower than 500 µs/div, the oscilloscope can acquire more samples than can fit into MegaZoom memory. The oscilloscope selects samples to store such that no local minimum or maximum wider than 1 ns is missed. In peak detect mode, narrow glitches and sharp edges are displayed more brightly
All points displayed after Single or Stop
After a Single acquisition or when the oscilloscope has been stopped, all acquired points are displayed.
Acquisition Modes
Average Mode
Averaging lets you average multiple triggers together to reduce noise and increase resolution. Averaging of multiple triggers requires a stable trigger. The number of triggers being averaged is displayed in the # Avgs softkey.
• Turn the Entry knob to set the number of averages (# Avgs) that best eliminates the noise from the displayed waveform.
The number of averages can be set from 1 to 16383 in powers-of-2 increments. The higher the number of averages you set, the more noise reduction and resolution enhancement will be accomplished.
High-resolution mode (# Avgs=1)
HIgh-resolution mode is an oversampling technique used when the digitizer sampling rate is faster than the rate at which samples are being stored into acquisition memory. For example, if the oscilloscope is sampling at 200 MSa/s, yet storing the samples at 1 MSa/s, it needs to store only 1 out of every 200 samples. When high-resolution mode is used, the slower the sweep speed, the greater the number of samples that are averaged together for each display point. This tends to reduce random noise on the input signal, which produces a smoother trace on the screen.
# Avgs Bits of resolution
1 8
4 9
16 10
64 11
Acquisition Modes
If you cannot acquire multiple triggers, you can still reduce noise and increase resolution at slower sweep speeds by setting # Avgs to 1.
Realtime Mode
In Realtime mode, the oscilloscope produces the waveform display from samples collected during one trigger event. The sample rate for the
54620-series is 200 MSa/s for single channel or 100 MSa/s with channel pairs 1 and 2, 3 and 4, or pod 1 and pod 2 running. The sample rate for the 54640-series is 2 GSa/s for single channel or 1 GSa/s with channel pairs 1 and 2, or pod 1 and pod 2 running.
When less than 1000 samples can be collected in the time spanned by the screen, a sophisticated reconstruction filter is used to fill in and enhance the waveform display.
To accurately reproduce a sampled waveform, the sample rate should be at least four times the highest frequency component of the waveform. If not, it is possible for the reconstructed waveform to be distorted or aliased. Aliasing is most commonly seen as jitter on fast edges.
When Realtime mode is off, the oscilloscope produces the waveform display from samples collected from multiple triggers, when on fast sweep speeds. In this case, the reconstruction filter is not used. When the trigger is stable, this produces the highest fidelity waveform.
Realtime mode is only necessary at sweep speeds of 200 ns/div and faster for the 54620-series and 2 µs/div and faster for the 54640-series, since on these ranges <1000 samples can be collected on each trigger. While the effective bandwidth of the channel is reduced slightly, Realtime mode produces a complete waveform for each trigger.
Realtime can be turned on when any other acquisition mode is turned on. Use Realtime to capture infrequent triggers, unstable triggers, or complex changing waveforms, such as eye diagrams.
54620-series Sweep speed 54640-series Sweep speed Bits of resolution (# Avgs=1)