Справочник Пользователя для National Instruments NI WLS/ENET-9163

When the reference trigger occurs, the NI WLS/NET-9163 Series device 
continues to write samples to the buffer until the buffer contains the number 
of posttrigger samples desired. Figure 10 shows the final buffer.

Figure 10.  Reference Trigger Final Buffer

To use ai/ReferenceTrigger with a digital source, specify a source and an 
edge. PFI 0 can provide the source. Refer to the Device Routing in MAX 
topic in the NI-DAQmx Help or the LabVIEW Help in version 8.0 or later 
for more information. 

The NI-DAQmx Help is available after installation from Start»Programs»
National Instruments»NI-DAQ»NI-DAQmx Help. To view the 
LabVIEW Help, in version 8.0 or later, select Help»Search the LabVIEW 
Help in LabVIEW. Alternately, to download the LabVIEW Help, go to 

ni.com/manuals

.

You also can specify whether the measurement acquisition stops on the 
rising edge or falling edge of ai/ReferenceTrigger.

The Pause Trigger signal can be generated from external sources. Any time 
the signal deasserts, you can use the Pause Trigger signal to pause the 
acquisition. 

You can use the AI Pause Trigger (ai/PauseTrigger) signal to pause and 
resume a measurement acquisition. The internal sample clock pauses while 
the external trigger signal is active and resumes when the signal is inactive. 
You can program the active level of the pause trigger to be high or low.

To use ai/PauseTrigger, specify a source and a polarity on PFI 0. 

Reference Trigger 

Pretrigger Samples

Complete Buffer 

Posttrigger Samples