Keithley KUSB-3100, Руководство пользователя

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Principles of Operation
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Continuous Output Mode
Use continuously paced analog output mode if you want to
accurately control the period between D/A conversions or write a
waveform to one or more analog output channels.
Use software to configure the output channel list, as described on
page 16 . Then, allocate a buffer that contains the values to write to the
analog output channels that are specified in the output channel list.
For example, if your output channel list contains DAC0 and DAC1,
specify your buffer as follows: first value for DAC0, first value for
DAC1, second value for DAC0, second value for DAC1, and so on.
When it receives the software trigger, the module starts writing
output values to the analog output channels specified in the output
channel list. The operation repeats continuously until either all the
data is output from the buffers (if buffer wrap mode is none) or you
stop the operation (if buffer wrap mode is multiple). Refer to
page 21
for more information about buffer modes.
Note: Make sure that the host computer transfers data to the analog
output channels fast enough so that they do not empty completely;
otherwise, an underrun error results.
To select continuously paced analog output mode, use software to
specify the data flow as continuous, the buffer wrap mode as none or
multiple, the trigger source and output clock as internal, and the
output clock frequency (between 30 Hz and 50 kHz).