Getting Started With Do Applications In Software; Digital Input/Output Configuration For Ni 9401; Pfi With Ni-Daqmx - National Instruments cRIO-904 Series User Manual

Figure 44. DO Pause Trigger with Other Signal Source
Using a Digital Source
To use DO Pause Trigger, specify a source and a polarity. The source can be a PFI signal or
one of several other internal signals on the cRIO controller.
You also can specify whether the samples are paused when DO Pause Trigger is at a logic high
or low level. Refer to the "Device Routing in MAX" topic in the NI-DAQmx Help or the
LabVIEW Help for more information.

Getting Started with DO Applications in Software

You can use the cRIO controller in the following digital output applications:
• Single-point (on-demand) generation
• Hardware-Timed Single Point generation
• Finite generation
• Continuous generation
For more information about programming digital output applications and triggers in software,
refer to the NI-DAQmx Help or to the LabVIEW Help.

Digital Input/Output Configuration for NI 9401

When you change the configuration of lines on a NI 9401 digital module between input and
output, NI-DAQmx temporarily reserves all of the lines on the module for communication to
send the module a line configuration command. For this reason, you must reserve the task in
advance through the DAQmx Control Task before any task has started. If another task or route
is actively using the module, to avoid interfering with the other task, NI-DAQmx generates an
error instead of sending the line configuration command. During the line configuration
command, the output lines are maintained without glitching.

PFI with NI-DAQmx

You can configure channels of a parallel digital module as Programmable Function Interface
(PFI) terminals. The cRIO controller also provides one terminal for PFI. Up to two digital
modules can be used to access PFI terminals in a single controller
You can configure each PFI individually as the following:
• Timing input signal for AI, AO, DI, DO, or counter/timer functions
• Timing output signal from AI, AO, DI, DO, or counter/timer functions
Pause Trigger
Sample Clock
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