How do you abort the Scope Fetch before a trigger occurs.

Question

I'm using a NI PCI 5112 scope card.  I've configured the start trigger on PFI 1 input with no timeout.   There does not appear to be any way to abort or reset the hardware once the niScope Fetch Binary 8.vi is waiting for the start trigger.  Does anyone know how to kill the niScope Fentch Binary 8.vi before the trigger is recieved?  (winthout restarting the computer!!!)
I'm programming in LabVIEW 7.1.1

Answer 1

As long as you are in the Fetch call, all other calls to the Scope
driver will block until Fetch exits.  That's why the Abort doesn't
do anything.  You have two options:
  1) Use a finite timeout.  Obviously, you are running into
cases in which the trigger does not arrive, and want to exit
cleanly.  This is exactly what the timeout is for.
  2) Determine the acquisition state before calling fetch. 
If this is a finite, single-record acquisition, poll on acquisition
status and do not call fetch until the status is 1 (acquisition
complete).  If you're doing a finite, multi-record acquisition,
poll on the Fetch>>Records Done property and only fetch the
records that have completed.  If you're doing a continuous
acquisition, poll on the Fetch>>Points Done or Fetch>>Fetch
Backlog property and only fetch the number of points that have been
acquired.
There's no clean way to break the infinite timeout fetch without forcing LabVIEW to close.