Error -200946 Using a NI DAQ Device

Updated Jul 15, 2018

Reported In


  • USB-6363


  • LabVIEW


  • NI-DAQmx

Issue Details

  • I get error -200946 when using my USB DAQ device.
  • The error is intermittent, or doesn't always happen within the same time frame.
  • This message sometimes happens when my application has been running for a long time.

Error -200946 occurred at Untitled 1


Possible reason(s):


Task could not be started, because the driver could not write enough data to the device.  This was due to system and/or bus-bandwidth limitations.


Reduce the number of programs your computer is executing concurrently.  If possible, perform operations with heavy bus usage sequentially instead of in parallel.  If you can't eliminate the problem, contact National Instruments support at


There's a lot of activity in the USB bus. Perhaps the application is writing too fast to the device, or maybe there's something else connected by USB that's slowing down the application.

  • Try disconnecting other USB devices
  • Plug the USB DAQ device to the back plane of the computer (in case you have a Desktop PC running this application, since those USB ports usually go directly to the motherboard, and have less traffic).
  • Read/write slower to the device.


If you're using a virtual machine, refer to the article Are NI Products Supported on Virtual Machines (VMs)?

Additional Information

The error happens because the communication bus is not responding as fast as needed.


Not Helpful