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The data acquisition device supplies its data in a constant stream of data. For each sample, the driver generates a conversion result for each channel. Because the user mode application runs in a multitasking environment, processing time for each sample can not be guaranteed. This is why samples need to be buffered. Before a measurement is started, the size of this buffer needs to be set. We also need to set the required sample rate of the measurement. Both of these settings are done with the function SetSignalBuffer. It is not possible to set or select individual channels of the frontend.

After the SetSignalBuffer function completes successfully, Start can be called. This will start the generation of samples. All samples for all channels of a device are stored in the allocated signal buffer. It is now is the task of the application to read these samples from the buffer as they become available. If the application cannot keep up with generated samples the buffer will overrun and data is lost. The application can call GetBufferInfo to get information about the status of the signal buffer.

Reading the samples from the signal buffer is done by calling GetSamples. The samples read from the buffer are automatically removed from it. The format of the sample data depends on the frontend that is used. Application needs the information returned by GetSignalFormat to interpret this sample data. 

 

 

Also see

Start, Stop, SetSignalBuffer, GetBufferInfo, GetSamples, GetSignalFormat