7-7
IM 701730-01E
Waveform Acquisition
7
• Sample Rate and Number of Moving Average Points
Sample Rate
Number of Moving Average Points
When interleave mode is OFF
When interleave is ON
500 MS/s
BoxAverage unavailable
2 points every two points of 1 GS/s
200 MS/s
2 points every 2 points of 400 MS/s
4 points every 4 points of 800 MS/s
100 MS/s
4 points every 4 points of 400 MS/s
8 points every 8 points of 800 MS/s
50 MS/s
8 points every 8 points of 400 MS/s
16 points every 16 points of 800 MS/s
20 MS/s
16 points every 20 points of 400 MS/s
32 points every 40 points of 800 MS/s
10 MS/s
32 points every 40 points of 400 MS/s
64 points every 80 points of 800 MS/s
5 MS/s
64 points every 80 points of 400 MS/s
128 points every 160 points of 800 MS/s
2 MS/s
128 points every 200 points of 400 MS/s
256 points every 400 points of 800 MS/s
1 MS/s
256 points every 400 points of 400 MS/s
256 points every 800 points of 800 MS/s
500 kS/s or
256 points every 800* points of 400 MS/s 256 points every 1600* points of 800 MS/s
less
* The interval at which data is resampled varies depending on the sample rate. However, the
maximum number of data points that is box averaged is 256.
• Possible Record Lengths
DL1720E:
250 kWords or less (500 kWords or less when in interleave mode)
DL1735E/DL1740E: 500 kWords or less (1 MWords or less when in interleave mode)
DL1740EL:
2 MWords or less (4 MWords or less when in interleave mode)
• Possible Sample Rates
The rate can be set at 200 MS/s or less (or 500 MS/s or less when in interleave
mode).
If the sample rate exceeds 200 MS/s (or 500 MS/s when in interleave mode), the
acquisition mode is set to normal mode even when box average is specified.
Acquisition Count
You can set the acquisition count. If you set the value to Infinite, acquisition will continue
until you press the START/STOP key. The default setting is Infinite. You cannot change
the acquisition count while measurement is in progress. Stop the measurement first.
Normal, Envelope, and Box Average: 2 to 65536 (1 step), Infinite
Averaging:
2 to 65536 (2
n
steps), Infinite
Notes on Averaging
• Averaging is effective only for repetitive waveforms.
• Correct averaging is not possible if the waveform has imperfect triggering (incomplete
synchronization), and the displayed waveform will be distorted. When working with
this type of signal, set the trigger mode to Normal, so that the waveform display is
updated only when the trigger is activated (see section 6.1).
• Roll mode display is disabled when averaging is used.
• If you stop waveform acquisition by pressing the START/STOP key, the averaging
process also stops. Averaging restarts from the beginning when acquisition resumes.
• If you are using simple averaging, the instrument terminates acquisition automatically
when it completes the specified number of acquisitions (acquisition count).
• When in repetitive sampling mode, only exponential averaging is executed.
7.5 Setting the Acquisition Mode
