ADLINK PCI-9810 - Manual (Page 47)

Operation Theory 35
X Middle-trigger acquisition
Use middle-trigger acquisition to collect data before and after a
specified trigger event. The amount of data acquired before a
trigger event occurs when using middle trigger may not equal
to the specified count of data, just like the pre-trigger mode.
Figure 5-3: Middle-trigger Acquisition
The desired number of samples after trigger event is pre-
loaded in post trigger counter register and will count down on
the rising edge of ADC sampling clock after the trigger
condition is met. When the count reaches 0, the counter stops.
The trigger can either be an external analog trigger or digital
trigger.
X Delay-trigger acquisition
Use delay trigger acquisition to delay the data collection after
the specified trigger event occurs. The delay time is controlled
by the value that is pre-loaded in the post trigger counter
register. The counter then counts down on the rising edge of
ADC sampling clock after the trigger condition was met.
When the count reaches 0, the counter stops and PCI-9812/
9810 starts to acquire data.
Figure 5-4: Delay-trigger Acquisition