Operation Theory
31
X
SI_counter (32-bit)
Specify the Scan Interval = SI_counter / Timebase
X
SI2_counter (24-bit)
Specify the Data Sampling Interval = SI2_counter/Timebase
X
PSC_counter (31-bit)
Specify the Post Scan Counts after a trigger event
X
NumChan_counter (8-bit)
Specify the number of samples per scan
The acquisition timing and the meaning of the four counters are
illustrated in Figure 4-4.
Timebase Clock Source
In scan acquisition mode, all A/D conversions start on the
output of counters which use Timebase as the clock source.
Through the software, you can specify the Timebase as the
internal clock source (onboard 80 MHz).
Figure 4-4: Scan Timing
Two trigger sources are available to start the scan acquisition.
Refer to section 4.6 for details. For data transfer mode, refer to the
Bus-mastering DMA Data Transfer section.
Summary of Contents for NuDAQ PCI-9222
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