Eirc,
Actually, the computer memory is always used in transfers. The driver automatically creates a PC buffer for each task. It then determines the best way to write this information to the card's FIFO (yours is 8192 samples, see the
datasheet for more info). There are, of course, ways to manually control this behavior, such as the "use onboard memory only" property, or the "do not allow regeneration" property, which prevents the DAC from outputting old data. The latter property requires your application to continuously supply new data - it will not repeat existing data, as in the default behavior. Please let us know if you have any additional questions.
Hope this helps,
Ryan Verret
Product Marketing Engineer
Signal Generators
National Instruments