National Instruments DAQ X Series, Руководство пользователя

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Chapter 4 Analog Input
X Series User Manual 4-32 ni.com
Using an External Source
Use one of the following external signals as the so u rce of AI Convert
Clock:
• PFI <0..15>
• RTSI <0..7>
• PXI_STAR
• PXIe-DSTAR<A,B>
• Analog Comparison Event (an analog trigger)
Routing AI Convert Clock Signal to an Output Terminal
Yo u can ro u te AI Convert Clock (as an active low signal) o u t to any
PFI <0..15>, RTSI <0..7>, or PXIe-DSTARC terminal.
All PFI terminals are config u red as inp u ts by defa u lt.
Using a Delay from Sample Clock to Convert Clock
When u sing the AI timing engine to generate yo u r Convert Clock, yo u also
can specify a config u rable delay from AI Sample Clock to the first AI
Convert Clock p u lse within the sample. By defa u lt, this delay is three ticks
of AI Convert Clock Timebase.
Fig u re 4-17 shows the relationship of AI Sample Clock to AI Convert
Clock.
Figure 4-17. AI Sample Clock and AI Convert Clock
AI Convert Clock Time bas e
AI Sa mple Clock
AI Convert Clock
Del a y from
Sa mple
Clock
Convert
Period
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