Contec AI-1204Z-PE, Справочное руководство

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AI-1204Z-PE Reference Manual
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Data acquisition in user buffer
When using a user buffer, the conversion data is transferred directly to application memory by the driver.
The figure above shows how to set the data in the user buffer for the case when 2channels (0 and
1channel) are used. Data transfer is performed using a single 4-byte packet which is the minimum
data transfer size.
Each packet contains two DA conversion data values in binary format. In the above example, the
lower two bytes of the packet contain the channel 0 data and the upper two bytes contain the
channel 1 data.
When using 2channels, each packet (each data transfer) contains the data for one sampling.
The figure above shows how to set the data in the user buffer for the case when 3channels (0, 1, and
2channels) are used. As each packet contains two conversion data values, the uppermost two bytes
are not used if an odd number of channels is being used, as in the example above. When using
3channels, two packets (two data transfer operations) are used for each sampling.