Acquire Continuous Samples with Repeating Trigger Source

[Steve_G]

Hi,

I have found this article http://zone.ni.com/devzone/cda/epd/p/id/5009, and the vi attached to it will do everything that I need.  I want to acquire Continous Samples at a specific sampling rate based on an external trigger on PFI0.  Pretty straightforward stuff.  However, the trigger signal on PFI0 will repeat at regular intervals (every 0.1 seconds or so).  I want the vi to acquire continuously but to be triggered on the first instance of the trigger on PFI0 and then to ignore the rest of the repeating triggers.  It may acquire for up to 10 seconds after that initial trigger, and after the time limit is expired I'll call the DAQmx Clear Task vi.

Will the vi in this article do this, or does it need to be modified in some way to only accept the first instance of the trigger?

Thanks.

Steve

[Kevin_Price · Accepted solution]

You're in luck.  Responding to the 1st trigger and ignoring subsequent ones is the normal default behavior.  Retriggering multiple times takes extra work (and compatible data acq hw) to configure.

So yes, the triggering in the article you linked should work just like you want.  Note however that the example is designed to use an external signal as a sample clock.  If you just want to use the board's internal timing engine for a specified sampling rate, you can specify 'OnboardClock' to be the Clock Source on the front panel.

-Kevin P

[Steve_G]

Kevin,

Thanks a lot.  You gave me the answer I was hoping for!  Thanks also for the info about the clocking.

Steve