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The trigger event occurs after the specified amount of data has been acquired. However,
if the trigger event occurs before the specified amount of data has been acquired, the
acquisition engine will ignore the trigger signal until the specified amount of data has been
acquired. Refer to Figure 3-13 for an example.
Time
Operation start
Acquisition start
Trigger
Data
Trigger Event Occurs
Acquisition stop
Begin to transfer data to system
N samples
X samples have been acquired
before trigger occurs, where
X<N
Trigger signals that occur before
the specified amount of data has
been acquired will be ignored.
Figure 3-13: Pre-trigger Mode Operation
3.5.3 Middle-trigger Acquisition
Use middle-trigger acquisition when you want to collect data before and after the trigger
event. The amount of stored data before and after trigger event can be set individually (M
and N samples), as illustrated in Figure 3-14.
Time
Operation start
Acquisition start
Trigger
Data
Acquisition stop
Begin to transfer data to system
N samples
M samples
Trigger event occurs
Figure 3-14: Middle-trigger Mode Operation
Please note that trigger event can only accepted when the specified amount of data has
been acquired (M samples). If the sampled data is not enough, the trigger event will be
ignored.
3.5.4 Delay-trigger Acquisition
Use delay-trigger acquisition to delay the data collection after the trigger event, as
illustrated in Figure 3-15. The delay time is specified by a 32-bit counter value so that the
