Acqiris U5309A User Manual page 26

2.4 Real-time averaging (AVG option)
Data readout when using FetchAccumulatedWaveformInt32
The data returned by the driver is unsigned. Since the API is limited to signed data type (for AVG fetch
Int32), a conversion should be applied to interpret data returned through API as unsigned int (32-bit) as
in provided examples.
IVI-C
To convert from raw value to Volts:
ViReal64 valueInVolts = static_cast<ViUInt32>(dataArray[firstValidPoint[currentRecord] + cur-
rentPoint]) * scaleFactor + scaleOffset;
IVI.NET
To convert from raw value to Volts:
IAqMD3AccumulatedWaveformCollection<Int32> waveformCollection = null ;
waveformCollection = instrument.Channels[«Channel1»].Measurement.FetchAccumulatedWaveform(0,
nbrRecords, 0, nbrSamples, waveformCollection);
foreach (var waveform in waveformCollection)
{
for (int point = 0; point < waveform.ValidPointCount; ++point)
{
}
}
Partial readout after an incomplete accumulation
It is possible to read data after an incomplete accumulation. If user stops the acquisition using an
Acquisition.Abort before reaching the specified number of triggers, the accumulated data can be
read, excepted for incomplete block of 8 triggers. For instance:
- If the number of acquired triggers is <8, no data is available.
- If the number of acquired triggers is between 8 and 16, the data accumulation for the first 8 triggers
can be read.
- If the number of acquired triggers is between 16 and 24, the data accumulation for the first 16 triggers
can be read.
And so on in multiple of 8 accumulations.
After an Acquisition.Abort and an incomplete accumulation, the ScaleFactor and
ScaleOffset returned by the Fetch function refer to the complete accumulation.
In case of partial average readout, the effective scale factor is obtained from the returned
ScaleFactor multiplied by the configured number of averages, and divided by the actual number
of averages.
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double sampleInVolts = waveform.GetScaled(point);
U5309A User's Manual