ADLINK PXI-2502 - Manual (Page 39)

Operation Theorem
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Delay-Trigger Generation
Use delay-trigger when users want to delay the waveform generation after
the trigger signal. The delay time is determined by DLY1_counter, as
shown in Figure 4.2.5.
The counter counts down on the rising edges of DLY1_counter clock
source after the start trigger signal. When the count reaches zero,
DAQ/PXI-2500 series starts to generate the waveform. The DLY1_counter
clock source can be software selected from the Internal 40MHz Timebase,
external clock input (AFI-0), or GPTC output 0/1.
Post-Trigger or Delay-Trigger with Retrigger
Use post-trigger or delay-trigger with retrigger when users want to gener-
ate multiple waveforms with respect to multiple incoming trigger signals.
Users can set Trig_counter to specify the number of acceptable trigger
signals.
Figure 4.2.6 illustrates an example. Two waveforms are generated after
the first trigger signal (Iterative Waveform Generation is used in this
example, please refer to Section 4.2.2.3 for details). The board then waits
for another trigger signal. When the next trigger signal is asserted, the
board generates two more waveforms. After three trigger signals, as
specified in Trig_Counter, no more triggers signals will be accepted unless
software trigger reset command is executed.
NOTE: Start Trigger signals asserted during waveform generation
process will be ignored.
(UC _Counter=8, IC_Counter=1)
8 update counts, 1 iteration
DAWR
WFG_in_progress
Operation start
Trigger
Output Waveform
0
2
4
6
3
-4
-2
4
Figure 4.2.4 Post-Trigger Generation