Support Question of the Week: Using the Beagle USB Protocol Analyzer, How Do I Capture Large Data Streams Overnight?

I'm working on a project where I need to continuously capture data - I'll be running the system overnight with the BeagleTM USB 480 Protocol Analyzer. My questions:

  • How much data can the Beagle USB protocol analyzer capture?
  • Running the system overnight, will all data be captured?
  • What do I need to set up or configure to do this?

Thanks for your question! The Beagle USB 480 analyzer contains a 64 MB on-board buffer, which serves two purposes:

  1. Buffer large data flows during real-time capture if the analysis computer cannot stream the data off the Beagle analyzer fast enough.
  2. Provide a delay for time to download and store all of the captured data.

In addition, to save memory space, you can also use the Data CenterTM Software and configure the capture settings: "Capture Settings - General and Capture Settings - General features - Circular Buffer enable" and "Settings - General and Capture Settings - USB features". For information, please refer to Data Center manual, section 4.14 and section 6.2, respectively. Following is a summary of the data capture options:

 

Configuring the Data Center Software Capture Settings to Save Memory for Storing Data Figure 1: Data Center Software - Capture and Circular Settings

 

  • The capture data limit setting limits the amount of memory that captured data can occupy on the analysis computer. Once this limit is reached, the capture will either automatically stop or records will begin to be deleted, depending on the circular buffer setting.
  • A slider in the capture settings window allows the capture data limit to be set as percentage of available memory. The slider can only be set to percentages that correspond to a valid capture data limit. The capture data limit must be at least 16 MB and no greater than 80% of available system memory
  • The software circular buffer option allows the Data Center application to discard past records during a capture in order to keep the capture size below the capture data limit.

The Data Center software has two modes of operation during capture with a Beagle USB 480 Protocol Analyzer (refer to section 6.7 of the Data Center User Manual).

  • Sequential – Saves the necessary information to display the capture in time-ordered Packet View.
  • Aggregate – Discards the information that was saved in Sequential Mode, which reduces memory usage. Note - using this mode disables the ability to use Packet View.  By default, the Data Center software compresses individual data-less sequences, which reduces memory usage during capture with the Beagle USB protocol analyzer.

In addition, six hardware filters can be used to save memory space. Utilizing this will filter out data-less transactions in the hardware, such as IN+NAK and PING+NAK combinations. The unwanted data is discarded, which reduces the amount of captured data on the device, the amount of analysis traffic back to the analysis PC, and the processing overhead on the analysis PC. For additional information about the hardware filter, please refer to section 6.3.4 of the Data Center manual.

The Beagle 480 Protocol Analyzer provides three different capture modes: real-time capture, real-time capture with overflow protection, and delayed-download. You can configure the capture mode based on your system requirements. For additional information about the capture mode, please refer to section 3.4 of the Beagle Analyzer User Manual

USB 2.0 data can also be filtered LiveFilter. However, this feature does not save memory space. For additional information, please refer to the Data Center User Manual at section 4.8, section 5.5 and section 6.11. For more information, please refer to the following documents.

Beagle User Manual
Data Center Software User Manual
Total Phase Products
Product Selector Guide

We hope this answers your question. If you have other questions about our host adapters or other Total Phase products, feel free to email us at sales@totalphase.com or submit a request for technical support. 

 

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