National Instruments NI USB-621x User Manual

Chapter 4 Analog Input
© National Instruments Corporation 4-23 NI USB-621x User Manual
Using a Digital Source
To use ai/ReferenceTrigger with a digital source, specify a source and an
edge. The source can be the PFI <0..3> or PFI <8..11> signals.
The source also can be one of several internal signals on your DAQ
device. Refer to Device Routing in MAX in the NI-DAQmx Help or the
LabVIEW 8.x Help for more information.
You also can specify whether the measurement acquisition stops on the
rising edge or falling edge of ai/ReferenceTrigger.
Routing AI Reference Trigger Signal to an Output
Terminal
You can route ai/ReferenceTrigger out to any PFI <4..7> or PFI <12..15>
terminal.
AI Pause Trigger Signal
You can use the AI Pause Trigger (ai/PauseTrigger) signal to pause and
resume a measurement acquisition. The internal sample clock pauses while
the external trigger signal is active and resumes when the signal is inactive.
You can program the active level of the pause trigger to be high or low.
Using a Digital Source
To use ai/SampleClock, specify a source and a polarity. The source can be
the PFI <0..3> or PFI <8..11> signals.
The source also can be one of several other internal signals on your DAQ
device. Refer to Device Routing in MAX in the NI-DAQmx Help or the
LabVIEW 8.x Help for more information.

National Instruments NI USB-621x Specifications

General

Brand	National Instruments
Model	NI USB-621x
Category	Computer Hardware
Language	English