DAQmx Error -50808 USB Transfer Failed Due to a Transaction Failure

Updated Jan 11, 2019

Reported In


  • CompactDAQ Chassis
  • cDAQ-9178


  • NI-DAQmx

Issue Details

DAQmx throws Error -50808 when adding or removing another USB device or when the USB DAQ or cDAQ device has been used for a while. Sometimes the error occurs after 30 minutes of using the device or after days of use before the device stops communicating. Resetting the device or restarting the task results in the same error.

In DAQmx version 9.3.5 and earlier Error -50405 is thrown instead.


To solve the error, you can try the following tests:

  • ​Disconnect the USB cable, then reconnect it
  • Remove power from the USB device, then reconnect it
  • Try replacing or using a different power supply and/or USB cable 
  • ​In Windows, disable, then re-enable the affected device through Windows Device Manager

NOTE: In some configurations, the steps above may cause Error -5080 on a different USB device connected to the same system.

Additional Information

When your system reports a USB transaction error, DAQmx aborts any tasks running on your USB device and throws Error -50808. According to Intel, a transaction error is any error that caused the host controller to think that the transfer did not complete successfully.

USB transaction errors can be caused by issues with the host controller, device, or cable and are not necessarily specific to NI hardware. Some host controllers are more susceptible to these errors than others. Connecting the device to a different host controller or replacing your USB cable may help decrease the likelihood of transaction errors.

To improve signal integrity and increase transaction reliability, NI recommends the following:

  • Use a shorter USB cable.

  • Eliminate intermediary connections between the host and the device: USB cable extenders should not be used.

  • Where necessary, use only powered USB hubs.
  • ​Make sure that the device is not overheating. Some devices will report their own temperature in NI MAX.


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