National Instruments Data Acquisition Device E Series - Manual (Page 52)

Chapter 2 Analog Input
© National Instruments Corporation 2-19 E Series User Manual
The output is an active high pulse. Figure 2-8 shows the timing behavior of
the PFI 1/AI REF TRIG pin configured as an output.
Figure 2-8. PFI 1/AI REF TRIG Timing Behavior
The PFI 1/AI REF TRIG pin is configured as an input by default.
AI Pause Trigger Signal
You can use the AI Pause Trigger (ai/PauseTrigger) signal to pause and
resume a measurement acquisition. This signal is not available as an output.
Using a Digital Source
To use ai/PauseTrigger, specify a source and a polarity. The source can be
an external signal connected to any PFI or RTSI <0..6> pin. The source can
also 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 8.x Help
for more information.
Also, specify whether the measurement sample is paused when
ai/PauseTrigger is at a logic high or low level.
Using an Analog Source
When you use an analog trigger source, the internal sample clock pauses
when the Analog Comparison Event signal is low and resumes when the
signal goes high (or vice versa). Refer to the
Triggering with an Analog
Source section of Chapter 10, Triggering , for more information on analog
trigger sources.
Note Pause triggers are only sensitive to the level of the source, not the edge.
t
w
t
w
= 50 to 100 ns