DAQmx Start Task VI Executes Slowly

Updated Jan 22, 2020

Reported In


  • LabVIEW


  • NI-DAQmx

Issue Details

In my LabVIEW code, the DAQmx Start Task VI takes an exceptionally long time to run. How can I speed up the execution of the Start Task VI?


When loading a DAQmx task in LabVIEW, the task loads through a series of states. The Start Task, Stop Task and Control Task VIs transition the task through these states. These states, and the transitions between them are as follows:
If the Start Task VI is called without any preceding Control Task VIs, then within the execution, it must transition the task from the Unverified state through each of the intermediate states through to the Running state. In larger tasks, reserving system resources and committing settings for these resources can take a long time, slowing the execution of the Start Task VI.

Alternatively, the Control Task VI can be used to transition the task to the Verified, Reserved or Committed states. Separating these steps from starting the task will reduce the execution time of the Start Task VI, which is especially valuable if the task is being started multiple times, or if starting the task is time sensitive.