Support Question of the Week: With a USB Protocol Analyzer, What is the Fastest and Most Accurate Way to Capture USB 2.0 Bus Data for a Sales Transaction?

I need to capture USB 2.0 bus data between a scanner and computer. The information is scanned from a coupon, and then OCR (optical character recognition) is applied to identify the information on that coupon - the amount to deduct from the purchase price. Currently, the process is slow and the result of the scan is not always accurate - the coupon often needs to be rescanned before the sale can be completed. In addition, the scanned information needs to be saved so that it can be printed on the purchase receipt. The file will be rewritten - that information does not need to be permanently saved after it is printed on the receipt and the sales transaction is completed.

Can you recommend which USB protocol analyzer to apply for this project? This is a large project - we will be updating 100 systems in our stores.

Also, which software applications do you recommend? I understand an “expression” can be set to start the reading., and then take the 50 next characters and save the data in a file. To make the sales transactions more efficient, I need the data in real-time.

Thanks for your questions! For your application, we recommend the Beagle USB 480 Protocol Analyzer, which is a robust non-intrusive device. It can monitor high-speed, full-speed, and low-Speed USB 2.0 (480 Mbps / 12 Mbps / 1.5 Mbps). The Beagle 480 has Real-Time USB class-level decoding with the Data Center Software, two capture modes (real-time and delayed-download), high-speed USB chirp detection, robust automatic speed detection, hardware-based packet suppression, and digital inputs and outputs for synchronizing with external logic. The Beagle 480 analyzer can also detect suspend/resume events and unexpected signals.

Using the USB 480 Protocol Analyzer to capture USB 2.0 bus data Figure 1: Beagle USB 480 Protocol Analyzer

You can capture USB 2.0 data with the Beagle 480 analyzer using the Data Center Software and the Beagle Software API.

  • The Data Center Software is a bus monitoring software application that displays captured USB bus data in true real-time through the Beagle analyzer. This eliminates the need to write custom software to control the analyzer. You can export the captured USB 2.0 Bus data to a CSV format file or to save it to a tdc file.
  • The Beagle Software API is used to control the analyzer, and to write a custom program for your defined specifications. API comes with support for multiple OS (Windows, Linux, and Mac) and multiple languages (C, Python, Visual Basic, and C#), and includes examples. We recommend using the Python bindings as it is a simple language, and a good option for scripting. For details about API functions, please refer to section 6 of the Beagle Protocol Analyzer User Manual.

For additional information, please refer to the following documents:

We hope this answers your questions. If you have other questions about our USB protocol analyzers or other Total Phase products, feel free to email us at or submit a request for technical support.

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