Ai Pause Trigger Signal; Figure 2-9. Halt (Internal Clock) And Free Running (External Clock) - National Instruments SC Express Series User Manual

Using an Analog Source
When you use an analog trigger source, the acquisition stops on the first rising edge of the
Analog Comparison Event signal.
Routing AI Reference Trigger Signal to an Output Terminal
You can route AI Reference Trigger out to any PXI_Trig <0..7>, or PXIe_DSTARC terminal.
All PFI terminals are configured as inputs by default.

AI Pause Trigger Signal

Use the AI Pause Trigger (ai/PauseTrigger) signal to pause and resume a measurement
acquisition. The internal sample clock pauses while the external trigger signal is active and
resumes when the signal is inactive. You can program the active level of the pause trigger to be
high or low, as shown in Figure 2-9. In the figure, T represents the period, and A represents the
unknown time between the clock pulse and the posttrigger.

Figure 2-9. Halt (Internal Clock) and Free Running (External Clock)

AI Sample Clock
AI Pause Trigger
AI External Sample Clock
AI Sample Clock
AI Pause Trigger
Using a Digital Source
To use AI Pause Trigger, specify a source and a polarity. The source can be any of the following
signals:
• PFI <0, 1>
• PXI_Trig <0..7>
• PXI_STAR
• PXIe_DSTAR <A, B>
The source also can be one of several other internal signals on your DAQ device. Refer to Device
Routing in MAX in the NI-DAQmx Help or the LabVIEW Help for more information.
T
Halt. Used on Internal Clock
Free Running. Used on External Clock
A
NI PXIe-4300 User Manual
T – A
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