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2-15
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)
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.
AI
Sa
mple Clock
AI P
aus
e Trigger
T
A
AI Extern
a
l
Sa
mple Clock
AI P
aus
e Trigger
H
a
lt. U
s
ed on Intern
a
l Clock
Free R
u
nning. U
s
ed on Extern
a
l Clock
T – A
AI
Sa
mple Clock
