Dataman 570 Series - Manual (Page 8)

Development kit for DATAMAN 570 series
Programmer’s Guide
2.4. Acquired data allocation
The array, that is passed as the first parameter of the GetData function must be at least
1048576 items long. Acquired data will be written in the array like this:
0 1048575 1048576 - MS 1048576 - AT 1048576 - lng
Fig. 2.4.1. – Data allocation in the array
MS is memory size, AT is amount of samples acquired after trigger, lng is amount of
received data (second parameter of the GetData function). If the AT+HoldOff >= MS,
MS equals to lng.
2.5. Measurement in the sampling mode
The DATAMAN 574 oscilloscope samples at 100MS/s in real time. To achieve a
higher sampling speed, the random sampling method is used.
2.5.1. Random sampling method
The sampling technology is applicable to periodical waveforms only. It is also known
as “random sampling” or “equivalent sampling”. It uses the fact, that the sampled
waveform is repeated periodically and the sampling clock is asynchronous regarding
to the waveform. The principle is shown on the figure 2.5.1.1. The sampled waveform
with triangle shape is sampled with the rising edge of the sampling clock.
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