DO Start Trigger Signal
Use the DO Start Trigger signal to initiate a waveform generation. If you do not use triggers,
you can begin a generation with a software command. If you are using an internal sample
clock, you can specify a delay from the start trigger to the first sample. For more information,
refer to the
NI-DAQmx Help
.
Using a Time Source
To use the Start Trigger signal with a time source, configure a specific time in NI-DAQmx.
Refer to the "Timestamps" and "Time Triggering" topics in the
NI-DAQmx Help
for more
information on accessing time-based features in the NI-DAQmx API.
Using a Digital Source
To use DO Start Trigger, specify a source and a rising or falling edge. The source can be one
of the following signals:
•
A pulse initiated by host software
•
Any PFI terminal
•
AI Reference Trigger
•
AI Start Trigger
The source also can be one of several internal signals on the cRIO controller. Refer to the
"Device Routing in MAX" topic in the
NI-DAQmx Help
or the
LabVIEW Help
for more
information.
You also can specify whether the waveform generation begins on the rising edge or falling
edge of DO Start Trigger.
Routing DO Start Trigger Signal to an Output Terminal
You can route DO Start Trigger to any output PFI terminal. The output is an active high pulse.
DO Pause Trigger Signal
Use the DO Pause Trigger signal to mask off samples in a DAQ sequence. When DO Pause
Trigger is active, no samples occur, but DO Pause Trigger does not stop a sample that is in
progress. The pause does not take effect until the beginning of the next sample.
When you generate digital output signals, the generation pauses as soon as the pause trigger is
asserted. If the source of the sample clock is the onboard clock, the generation resumes as soon
as the pause trigger is deasserted, as shown in the figure below.
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NI cRIO-905x User Manual