Ai Hold Complete Event Signal; Ai Start Trigger Signal - National Instruments X Series User Manual

Chapter 4 Analog Input
• 100 kHz Timebase
• PXI_CLK10
• RTSI <0..7>
• PFI <0..15>
• PXI_STAR
• PXIe_DSTAR<A,B>
• Analog Comparison Event (an analog trigger)
Note (NI PXIe-6386/6396 Devices)
several ways from other SMIO devices. For more information about these devices
related to AI Sample Clocks, go to
smio14ms
AI Sample Clock Timebase is not available as an output on the I/O connector. AI Sample Clock
Timebase is divided down to provide one of the possible sources for AI Sample Clock. You can
configure the polarity selection for AI Sample Clock Timebase as either rising or falling edge,
except on 100 MHz Timebase or 20 MHz Timebase.

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.

AI Start Trigger Signal

Use the AI Start Trigger (ai/StartTrigger) signal to begin a measurement acquisition. A
measurement acquisition consists of one or more samples. If you do not use triggers, begin a
measurement with a software command. Once the acquisition begins, configure the acquisition
to stop:
• When a certain number of points are sampled (in finite mode)
• After a hardware reference trigger (in finite mode)
• With a software command (in continuous mode)
An acquisition that uses a start trigger (but not a reference trigger) is sometimes referred to as a
posttriggered acquisition.
Retriggerable Analog Input
Note (PXIe-6386/6396 Devices)
currently support retriggerable AI tasks. For more information about special
4-50 | ni.com
.
PXIe-6386 and PXIe-6396 devices differ in
and enter the Info Code
ni.com/info
PXIe-6386 and PXIe-6396 devices do not