Chapter 3
Analog Output
Analog Output Series User Manual
3-10
ni.com
The output is an active high pulse. Figure 3-7 shows the timing behavior of
the PFI 5/AO SAMP CLK pin when the pin is an output.
Figure 3-7.
PFI 5/AO SAMP CLK as an Output
The PFI 5/AO SAMP CLK is configured as an input by default.
Other Timing Requirements
A counter on your device internally generates ao/SampleClock unless you
select some external source. The ao/StartTrigger signal starts this counter.
It is stopped automatically by hardware after a finite acquisition completes
or manually through software. When using an internally generated
ao/SampleClock in NI-DAQmx, you can also specify a configurable delay
from the ao/StartTrigger to the first ao/SampleClock pulse. By default, this
delay is two ticks of the ao/SampleClockTimebase signal.
Figure 3-8 shows the relationship of the ao/SampleClock signal to the
ao/StartTrigger signal.
Figure 3-8.
ao/SampleClock and ao/StartTrigger
t
w
= 50–75 n
s
t
w
a
o/
S
t
a
rtTrigger
a
o/
Sa
mpleClock
a
o/
Sa
mpleClockTime
bas
e
Del
a
y
from
S
t
a
rt
Trigger
