National Instruments NI USB-621x - Manual (Page 75)

Chapter 7 Analog Output
NI USB-621x User Manual 7-8 ni.com
Figure 7-5 shows the relationship of ao/SampleClock to ao/StartTrigger.
Figure 7-5. ao/SampleClock and ao/StartTrigger
AO Sample Clock Timebase Signal
The AO Sample Clock Timebase (ao/SampleClockTimebase) signal is
divided down to provide a source for ao/SampleClock.
You can route any of the following signals to be the AO Sample Clock
Timebase (ao/SampleClockTimebase) signal:
• 20 MHz Timebase
• 100 kHz Timebase
• PFI <0..3>, PFI <8..11>
ao/SampleClockTimebase is not available as an output on the I/O
connector.
You might use ao/SampleClockTimebase if you want to use an external
sample clock signal, but need to divide the signal down. If you want to use
an external sample clock signal, but do not need to divide the signal, then
you should use ao/SampleClock rather than ao/SampleClockTimebase.
ao/SampleClockTimebase
ao/StartTrigger
ao/SampleClock
Delay
From
Start
Trigger