User Guide

NI cDAQ-9172 User Guide and Specifications 32 ni.com
more information, refer to the NI-DAQmx Help. The NI-DAQmx Help
is available after installation from Start»All Programs»National
Instruments»NI-DAQ»NI-DAQmx Help.
Using a Digital Source
To use ao/StartTrigger, 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/ReferenceTrigger
• ai/StartTrigger
The source also can be one of several internal signals on the NI cDAQ-9172
chassis. Refer to the Device Routing in MAX topic in the NI-DAQmx Help
or the LabVIEW Help in version 8.0 or later for more information.
The NI-DAQmx Help is available after installation from Start»
All Programs»National Instruments»NI-DAQ»NI-DAQmx Help.
To view the LabVIEW Help, in version 8.0 or later, select Help»
Search the LabVIEW Help in LabVIEW. Alternately, to download
the LabVIEW Help, go to
ni.com/manuals.
You also can specify whether the waveform generation begins on the rising
edge or falling edge of ao/StartTrigger.
Using an Analog Source
Some C Series I/O modules can generate a trigger based on an analog
signal. In NI-DAQmx, this is called the Analog Comparison Event,
depending on the trigger properties.
When you use an analog trigger source, the waveform generation begins on
the first rising or falling edge of the Analog Comparison Event signal,
depending on the trigger properties. The analog trigger circuit must be
configured by a simultaneously running analog input task.
Routing AO Start Trigger Signal to an Output Terminal
You can route ao/StartTrigger to any output PFI terminal. The output is an
active high pulse.