ADLINK PCIe-9814 - Manual (Page 30)

20 Operations
Figure 3-7: Delayed Trigger Mode Acquisition
3.4.3 Pre-Trigger Mode
Collects data before the trigger event, starting once specified func-
tion calls are executed to begin the pre-trigger operation, and
stopping when the trigger event occurs. If the trigger event occurs
after the specified amount of data has been acquired, the system
stores only data preceding the trigger event by a specified
amount, as follows.
Figure 3-8: Pre-Trigger Mode Acquisition
3.4.4 Middle Trigger Mode
Collects data before and after the trigger event, with the amount to
be collected set individually (M and N samples), as follows
Time
Operation start
Acquisition start
Trigger
Data
Trigger Event Occurs
Acquisition stop
Data transfer to system begins
N samples
X samples have been acquired
before trigger occurs, where X<N
Trigger signals occuring before the specified
amount of data has been acquired are ignored