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Operation Theory
Note:
M_counter defined in Middle-Trigger is different from that of
Pre-Trigger. In Middle-trigger, M_Counter ends counting
before
the trigger event
while in Pre-Trigger, M_Counter ends counting
right at or before trigger event.
Please refer to figure 11 and
figure 15.
Post-Trigger Acquisition
Use post-trigger acquisition in applications where you want to collect data
after a trigger event. The number of scans after the trigger is specified in
PSC_counter, as illustrated in fig 16. The total acquired data length =
number of enable-channel * PSC_counter.
(PSC_Counter=3)
Acquisition_in_progress
Scan_start
ADCONV
Acquired & stored data
(3 scans)
Operation start
Trigger
Post Scan Count
3
2
1
0
Figure 16: Post trigger
Delay Trigger Acquisition
Use delay trigger acquisition in applications where you want to delay the
data collection after the occurrence of a specified trigger event. The delay
time is controlled by the value, which is pre-loaded in the
Delay_counter
(16bit)
.
The counter counts down on the rising edge of the Delay_counter
clock source after the trigger condition is met. The clock source can be
software programmed either by the TIMEBASE clock (40MHz) or A/D
sampling clock (TIMEBASE / SI_counter). When the count reaches 0, the
counter stops and the card starts to acquire data. The total acquired data
length = number of e nable-channel * PSC_counter.
