When Monitoring a USB Bus, I Am Capturing a Lot of Data Packets that I Don’t Need to See. How Can I Exclude the USB Data that Doesn’t Matter to Me?

Question from the Customer:

I am interested in the Beagle USB protocol analyzers, and I have very specific questions about the Data Center Software. What searching or filtering options do you offer?

The exact scenario is that I am looking to find and ideally exclude particular packets based on a given sequence within the packet data. For example, I would want to find all packets with 0xAA 0xBB 0xCC in the data, and filter out any packets with 0xDD 0xEE in the data. Is this possible?

Response from Technical Support:

Thanks for your question! Yes, filter and trigger options are available with our Beagle USB Protocol Analyzers. Your requirement can be fulfilled with the LiveFilterTM option in the Data Center Software, and it’s easy to do!

A summary of what LiveFilter does:

  • Filter for and against specific indices, errors, endpoints, device addresses, PIDs, data patterns, and more
  • Switch between filtered and non-filtered views with a single click

An overview of how LiveFilter works:

You can do this with the Data Center Software.  Enter the hex data to be filtered in LiveFilter tab under the Navigator. We have two examples to show you – the first we filtered 0xE1 0x81 0x58 and in the second we filtered out (excluded) 0x4B 0x1B 0x40.

Unfiltered Data

161887-beagle-unfiltered_data

Filter Matched Data Included

161887-beagle-filter_matched_data

Filter Matched Data Excluded

161887-beagle-filter_out_matched_dataFor more information about how this is done, you can watch this video that includes LiveFilter.



Note – this video shows you can use LiveFilter for I2C and SPI data streams as well.

You can also refer to section Filtering a Capture of the Data Center Protocol Analyzer User Manual.  For information about Software API, please refer to the API Documentation section of the Beagle Protocol Analyzer User Manual.

With the Beagle USB 5000 analyzers or the Beagle USB 480 Power Protocol Analyzer – Ultimate Edition, it is possible to use the advanced state-based matching system, also known as triggers, to execute a hardware filter to remove any data packets you don’t want to see from the capture entirely.  Then you could use the LiveFilter option to show only the packets you are interested in (and hide everything else).  Here’s a video on how to use the advanced state-based matching system:

https://youtu.be/6gsx0evRPuE



We hope this answers your questions. Additional resources that you may find helpful include the following:

More questions? More projects? You can contact us and request a demo that applies to your application, as well as ask questions about protocol analyzers and other Total Phase products.

Request a Demo