Windows USB Resource Error when Using Multiple NI USB Devices

Issue Details

• Not enough USB controller resources – the controller does not have enough resources for this device.
• You have exceeded the number of supported USB devices on the Host Controller. Please disconnect alternate USB device currently not being used or connect one of the devices to a different port. 

Solution

The number of USB devices is limited by the onboard USB host controllers and the processor. USB Host are designed to support a limited number of USB endpoints. If the number of endpoints connected exceeds the number supported by the USB host controller on your computer, Windows will throw an error indicating that the controller does not have sufficient resources for the device. 

The number of endpoints used by NI USB devices is not adjustable. Try the following steps to resolve the error:

• Unplug any USB devices that are not necessary for your application.
• Connect NI USB devices directly to the computer, rather than through a USB hub or extender.
• Distribute your USB devices evenly across multiple root ports or host controllers. 
  • You can see your computer’s available and installed host controllers in Windows Device Manager. 
  • If your computer has PCI, PCIe, or other types of expansion slots, you may be able to add additional host controllers with USB adapter cards.
• If you can replace the USB host controller on your computer, try a different chipset or brand.

One physical USB device can have more than one endpoint, e.g. a headset consisting of mic and speaker. A single USB device can allocate up to 32 endpoints. The total number of USB endpoints allowed is dependent on the USB host controller and its firmware. For some controllers, this number can be less than 100 total allowable USB endpoints. 

Since some NI USB devices can use up to 32 endpoints per device, you can exceed the number of allowable endpoints when connecting them to a USB hub. Some computer’s own internal USB ports and other internal devices are all tied to a single USB host controller, which can also lead to exceeding USB resources quickly. 

Additional Information

Newer NI PXIe controllers typically can have 64 devices and 128 endpoints. However, some controllers, especially older ones, only allow for 32 devices and fewer than 127 endpoints. You can use 3rd party tools to see how many devices and endpoints are being used, such as USB Device Tree Viewer. Note that NI does not endorse or maintain this tool. If your device has USB 3.0 ports, additional USB 2.0 ports may appear in the USB Device Tree Viewer, as they are used by the controller to manage the USB 2.0 devices plugged into the USB 3.0 port. These are internal and not user accessible. 

If you wish to add more USB host controllers to your PXIe System, you can do so via a PXIe-1095/1092/1084 Chassis (Timing and Sync Variant) or via a 3rd party PXIe USB card. If your PXIe controller has a Thunderbolt (TBT) port, you can add another USB Controller via a TBT dock. This will not work if you use a USB-C hub, which will function as a standard USB hub instead of adding another USB Controller.