User Guide

Using an Internal Source

To use di/SampleClock with an internal source, specify the signal source

and the polarity of the signal. Use the following signals as the source:

• AI Sample Clock

• AI Convert Clock

• AO Sample Clock

• Counter n Internal Output

•Frequency Output

• DI Change Detection Output

Several other internal signals can be routed to di/SampleClock. 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.

Using an External Source

You can route the following signals as di/SampleClock:

•Any PFI terminal

• Analog Comparison Event (an analog trigger)

You can sample data on the rising or falling edge of di/SampleClock.

Routing DI Sample Clock to an Output Terminal

You can route di/SampleClock to any output PFI terminal. The PFI

circuitry inverts the polarity of di/SampleClock before driving the PFI

terminal.

Digital Waveform Generation (Correlated Output)

With a hardware-timed generation, a digital hardware signal controls the

rate of the generation. This signal can be generated internally on the chassis

or provided externally.

Hardware-timed generations have several advantages over software-timed

acquisitions:

• The time between samples can be much shorter.

• The timing between samples can be deterministic.

Hardware-timed operations must be buffered.