Using A Time Source; Ao Pause Trigger Signal; Ao Pause Trigger With The Onboard Clock Source - National Instruments cRIO-904 Series User Manual

Using a Digital Source
To use AO 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 AO Start Trigger.
Routing AO Start Trigger Signal to an Output Terminal
You can route AO Start Trigger to any output PFI terminal. The output is an active high pulse.

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.

AO Pause Trigger Signal

Use the AO Pause Trigger signal to mask off samples in a DAQ sequence. When AO Pause
Trigger is active, no samples occur, but AO 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 analog 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 following figure.
Figure 37. AO Pause Trigger with the Onboard Clock Source
If you are using any signal other than the onboard clock as the source of the sample clock, the
generation resumes as soon as the pause trigger is deasserted and another edge of the sample
clock is received, as shown in the following figure.
58 | ni.com | cRIO-904x User Manual
Pause Trigger
Sample Clock