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

Updated Sep 5, 2023

Reported In


  • CompactDAQ Chassis
  • cDAQ-9178


  • NI-DAQmx

Issue Details

DAQmx Error -50808 occurs when adding or removing another USB device or when the USB DAQ or cDAQ device has been used for an extended period of time. The error may occur within 30 minutes or after multiple days of usage before the device stops communicating. Resetting the device or restarting the task results in the same error.
Error -50808 occurred.
Possible reason(s): 
NI Platform Services: A USB transfer failed due to a transaction error reported by the USB host controller. This may be due to a fault in the system's USB host controller, a USB cable, or a USB device.
Task Name:

Note: In DAQmx version 9.3.5 and earlier Error -50405 occurs 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 
  • Try connecting your device to another computer to verify device works
  • ​In Windows, disable, then re-enable the affected device through Windows Device Manager

Note: In some configurations, the steps above may cause Error -50808 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.

This error may come from a Windows setting named USB Selective Suspend, which removes power from idle USB devices to conserve power. For more information, please see article USB Device Disconnects and Reconnects Periodically on Windows PC.

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.
  • Check for potential ground loops that may be affecting the USB hub and use a USB isolator if there are ground loops present.