Ai Convert Clock Timebase Signal; Ai Hold Complete Event Signal - National Instruments DAQ X Series User Manual

Chapter 4 Analog Input
AI Sample Clock
AI Convert Clock
Channel Measured

AI Convert Clock Timebase Signal

The AI Convert Clock Timebase (ai/ConvertClockTimebase) signal is
divided down to provide one of the possible sources for AI Convert Clock.
Use one of the following signals as the source of AI Convert Clock Timebase:
•
•
AI Convert Clock Timebase is not available as an output on the I/O
connector.

AI Hold Complete Event Signal

The AI Hold Complete Event (ai/HoldCompleteEvent) signal generates
a pulse after each A/D conversion begins. You can route AI Hold Complete
Event out to any PFI <0..15>, RTSI <0..7>, or PXIe-DSTARC terminal.
The polarity of AI Hold Complete Event is software-selectable, but is
typically configured so that a low-to-high leading edge can clock external
AI multiplexers indicating when the input signal has been sampled and can
be removed.
X Series User Manual
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0
0 1 2 3
Sample #1
Figure 4-20. AI Sample Clock and AI Convert Clock Improperly Matched;
Leads to Aperiodic Sampling
AI Sample Clock
AI Convert Clock
Channel Measured 0 1 2 3
Sample #1
Figure 4-21. AI Sample Clock and AI Convert Clock Properly Matched
AI Sample Clock Timebase
100 MHz Timebase
4-34
1 2 3 0
Sample #2 Sample #3
0 1 2 3 0 1 2 3
Sample #2 Sample #3
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