ADLINK PCIe-9814 - Manual (Page 29)

Operations 19
PCIe-9814
3.4 Trigger Modes
Trigger modes applied to trigger sources initiate different data
acquisition timings when a trigger event occurs. The following trig-
ger mode descriptions are applied to analog input function.
3.4.1 Post Trigger Mode
Post-trigger acquisition is applicable when data is to be collected
after the trigger event, as shown. When the operation starts, PCIe-
9814 waits for a trigger event. Once the trigger signal is received,
acquisition begins. Data is generated from ADC and transferred to
system memory continuously. The acquisition stops once the total
data amount reaches a predefined value.
Figure 3-6: Post-Trigger Acquisition
3.4.2 Delayed Trigger Mode
Delayed-trigger acquisition is utilized to postpone data collection
after the trigger event, as shown. When PCIe-9814 receives a trig-
ger event, a time delay is implemented before commencing acqui-
sition. The delay is specified by a 16-bit counter value such that a
maximum thereof is the period of TIMEBASE X (2
16
), and the min-
imum is the Timebase period.