©
National Instruments Corporation
10-1
Analog Output Series User Manual
10
Triggering
A trigger is a signal that causes a device to perform an action, such as
starting an acquisition. You can program your DAQ device to generate
triggers on:
•
a software command
•
a condition on an external digital signal
You can also program your DAQ device to perform an action in response to
a trigger. The action can affect:
•
analog output generation
•
counter behavior
For more information, refer to the
section of
, and the
section of
.
Triggering with a Digital Source
Your DAQ device can generate a trigger on a digital signal. You must
specify a source and an edge. The digital source can be any of the PFI or
RTSI <0..6> signals.
The edge can be either the rising edge or falling edge of the digital signal.
A rising edge is a transition from a low logic level to a high logic level. A
falling edge is a high to low transition.
Figure 10-1 shows a falling-edge trigger.
Figure 10-1.
Falling-Edge Trigger
5 V
0 V
F
a
lling Edge Initi
a
te
s
Acq
u
i
s
ition
Digit
a
l Trigger