Contec ADA16-32/2(PCI)F, Руководство пользователя

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4. Functions
ADA16-32/2(PCI)F
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Data transfer method
You can select between device buffer mode, which saves conversion data in a conversion data memory
area either on the device or in the driver, or user buffer mode which saves the conversion data in
application memory.
- Device buffer mode
The application output data is first stored in the device buffer (memory on the device itself or in the
driver).
When conversion starts, the device starts outputting the output data.
The device buffer can operate as FIFO or RING memory.
Device buffer mode is simpler to use than user buffer mode as it handles conversion data by
sampling count and API functions are provided to set conversion data directly as voltage values.
As functions are provided to meet most practical requirements, device buffer mode is usually the
best option.
- User buffer mode
A region of application memory to store the output data is specified before starting conversion.
When conversion starts, the driver outputs the conversion data directly to the device.
Whether or not to overwrite memory can be specified in user buffer mode.
User buffer mode uses bus master transfer automatically on devices that support it.
Select user buffer mode if you wish to use bus master transfer.
Device buffer mode User buffer mode