Question from the Customer:
I am using the Beagle USB 12 Protocol Analyzer to monitor a High-speed USB bus. It detects no USB traffic or enumeration - what am I missing?
Response from Technical Support:Thanks for your question! The Beagle USB 12 Protocol Analyzer is a Low Speed and Full Speed USB sniffer that will only capture Low and Full Speed USB device traffic. Unless you are monitoring a HID (human interface device) such as mouse, mostly likely the USB speed exceeds the parameters of the Beagle USB 12 Protocol Analyzer. It is a great tool for a variety of HID products such as mice and keyboards, but not for USB devices that operate in High-speed mode.
Checking USB Device Speed
To see if speed is an issue, the USB Device Tree Viewer is the easiest way to see the device speed. When you run the USB Device Tree Viewer, you will see a list of USB Host Controllers. You can cycle through each port of the USB Root Hubs attached to these controllers to see what is connected to that port. Each USB device that is connected to your computer (mouse, Wi-Fi or Bluetooth adapter, webcam, etc.) will be shown on one of those ports. The Tree Viewer will also show the Device Bus Speed of the highlighted device. Here is an example of what could be displayed:
The displayed speed will be one of the following:
- 0x01 (Full-Speed, 12 Mbps)
- 0x02 (High-Speed, 480 Mbps)
- 0x03 (SuperSpeed, 5 Gbps/625 MBps)
Here is an example of what you could see on your computer:
High Speed Work Around
For an immediate work-around to monitor the data, you could place a Full speed USB Hub between the target High-speed USB device and the Beagle USB 12 Protocol Analyzer. The hub will force the device traffic down to 12 Mbps, which the Beagle USB 12 analyzer is capable of capturing. However, you would not be able to class decode the USB transactions. For greater support, we recommend one of our High-speed USB protocol analyzers.
High-Speed USB Protocol Analyzers
To capture, view, and analyze High-speed USB data, we recommend one of these protocol analyzers:
Each analyzer has its specifications and merits. To select which is best for your project, we recommend taking a look at our USB Analyzer Product Guide. For higher speeds and power concerns, the Beagle USB 480 Power Analyzer is a widely used tool. It offers class-decoding, triggers, and filtering, as well as the deepest USB 2.0 High-speed hardware buffer of our tools.
We hope this answers your questions. Additional resources that you may find helpful include the following:
If you want more information, feel free to contact us with your questions, or request a demo that applies to your application.