National Instruments PXI-6289 User Manual page 238

Reference Trigger
Use the Reference Trigger to stop the acquisition. It is normally used in pretrigger acquisitions;
it is necessary to acquire data before and after the trigger. The Reference Trigger signals the time
when the AI timing engine starts counting the number of posttrigger conversions to take before
stopping. The Reference Trigger can come from external or internal sources and its source is
selected with a multiplexer. Its output is called the Selected Reference Trigger.
Figure B-13. Reference Trigger and the Analog Input Timing Engine
Selected Reference Trigger
Terminal
Terminal
Terminal
Terminal
Terminal
Selected Reference Trigger
Sync Convert Clock Timebase
Reference Trigger
Selected Start Trigger
Selected Pause Trigger
Sample Clock Timebase
Sync Sample Clock Timebase
Convert Clock Timebase
Sync Convert Clock Timebase
Selected Sample Clock
Figure B-14. Reference Trigger Timing Diagram
_i
POUT
Reference Trigger
Start Trigger
Pause Trigger
SI Start
SI
Counter
Block
SI_TC
SI2
Counter
Block
Start
t
22
t
23
t
25
t
26
M Series User Manual
POUT
SI2_TC
1
t
24
t
26
© National Instruments | B-13
Terminal
Terminal
RTSI
Terminal
p_AI_Convert
Terminal