Behavior. A single waveform data point can be made up of several sequentially acquired data points. The waveform data points
can also be created from a composite of sampled data taken from multiple acquisitions. The acquisition modes determine how
the waveform data points are produced from the sampled data.
Sample. This mode creates a record point by saving one or more samples during each acquisition interval. Sample mode is the
default acquisition mode. The instrument does no post processing of acquired samples in this mode.
Pk Detect. Peak Detect mode alternates between saving the highest sample in one acquisition interval and the lowest sample in
the next acquisition interval. Peak Detect mode only works with real-time, noninterpolated sampling.
Hi Res. High Resolution mode averages all samples taken during an acquisition interval to create a record point. This average
results in a higher-resolution, lower-bandwidth waveform. This mode only works with real-time, noninterpolated sampling.
NOTE. A key advantage of Hi Res mode is its potential for increasing resolution regardless of the input signal. The following table
indicates that you can obtain up to 15 significant bits with Hi Res mode. Note that the resolution improvements are limited to
speeds slower than 40 ns/div.
Additional resolution bits
2.5 GS/s 8.5 bits 1.1 GHz
1 GS/s 9 bits 440 MHz
250 MS/s 10 bits 110 MHz
50 MS/s 11 bits 22 MHz
10 MS/s 12 bits 4.4 MHz
2.5 MS/s 13 bits 1.1 MHz
1 MS/s 14 bits 440 kHz
250 KS/s 15 bits 110 kHz
25 KS/s >15 bits 11 kHz
250 S/s >15 bits 110 Hz
25 S/s >15 bits 11 Hz
2.5 S/s >15 bits 1.1 Hz
Envelope. This mode acquires and displays a waveform record that shows the extremes in variations over several acquisitions.
The instrument saves the highest and lowest values in two adjacent intervals similar to Peak Detect mode. Unlike Peak Detect
mode, the peaks are gathered over many trigger events.
After each trigger event, the instrument acquires data and then compares the minimum and maximum values from the current
acquisition with those stored from the previous acquisition. The final display shows the most extreme values for all the
acquisitions for each point in the waveform record.
Acquiring and displaying a noisy square wave signal illustrates the difference between the modes. Note how Average mode
reduces the noise while Envelope mode captures its extremes:
Oscilloscope reference
772 DPO70000SX, MSO/DPO70000DX, MSO/DPO70000C, DPO7000C, and MSO/DPO5000B Series
To Next Page
Loading...
Need help?
General
