National Instruments pxi ni 5401 用户手册

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Chapter 2
Function Generator Operation
2-6
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Figure 2-5.  Single Trigger Mode
For example, assume that one cycle of a sine wave is stored in the DDS 
lookup memory. For stage 1, f1 specifies the sine frequency to be generated 
for time 
T1, f2 and 
T2 for stage 2, and so on. If there are four stages in 
the staging list, f4 will be generated continuously until the waveform 
generation is stopped.
Continuous Trigger Mode
The waveform you define in the staging list is generated infinitely by 
continually cycling through the staging list. After a trigger is received, the 
waveform generation starts at the first stage, continues through the last 
stage, and loops back to the start of the first stage, continuing until you stop 
the waveform generation. Only one trigger is required to start the waveform 
generation.
Figure 2-6 illustrates a continuous trigger mode of operation.
Figure 2-6.  Continuous Trigger Mode
Start Trigger
Last Stage Generated
Continuously Until Stopped
End of All Stages
f1,
 ∆
T1
f2,
 ∆
T2
f3,
 ∆
T3
f4
Start Trigger
End of All Stages
(f1,
 ∆
T1
)
(f2,
 ∆
T2
)
(f3,
 ∆
T3
)
(f1,
 ∆
T1
)
(f2,
 ∆
T2
)
(f4,
 ∆
T4
)
Repeat
Until Stopped