Chapter 10
Triggering
10-2
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Figure 10-1 shows a falling-edge trigger.
Figure 10-1.
Falling-Edge Trigger
You can also program your DAQ device to perform an action in response to
a trigger from a digital source. This action can affect the following:
•
Analog input acquisitions
•
Analog output generation
•
Counter behavior
Triggering with an Analog Source
Some E Series devices can generate a trigger on an analog signal.
Figure 10-2 shows the analog trigger circuit.
Figure 10-2.
Analog Trigger Circuit
You must specify a source and an analog trigger type. The source can be
either the PFI 0/AI START TRIG pin or an analog input channel. Refer to
the
section for more information.
5 V
0 V
Falling edge initiates acquisition
Digital Trigger
PGIA
ADC
+
–
Analog
Input
Channels
Analog
Trigger
Detection
Mux
PFI 0/AI
START TRIG
AI Circuitry
AO Circuitry
Counter Circuitry
Analog Comparison
Event
(Analog Trigger
Circuitry Output)