JYTEK NuDAQ PCI-69222, Руководство пользователя

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Operation Theory 41
You can choose the update clock source by setting the AO
source configuration. Refer to Figure 4-11. It is recommended that
you use the internal hardware to get a more precise update rate.
Figure 4-11: Waveform Generation Clock Source Selection
Waveform Generation with Internal Hardware Timer
Six counters interact with the waveform to generate different
DAWR timing to form various waveforms. These are described
in Table 4-4 and illustrated in Figure 4-12.
Counter Name Width Description Note
UI_counter 32-bit Update Interval .
Defines the update
interval between each
data output.
Update Interval =
UI_counter / Timebase*.
UC_counter 32-bit Update Counts .
Defines the number of
data in a waveform.
When value in
UC_counter is smaller
than the size of
waveform patterns, the
waveform is generated
piece-wisely.
IC_counter 32-bit Iteration Counts .
Defines how many
times the waveform is
generated.
DLY1_counter 32-bit Defines the delay time
for waveform generation
after the trigger signal.
Delay Time =
(DLY1_counter / Clock
Timebase)
Table 4-4: Summary of Counters for Waveform Generation
Internal
Timer
SSI
GPI[7..0]
AO update clock