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How Do I Sync the Clocks from Two USB Data Captures using Beagle USB Analyzers?
Rena Ayeras

Synchronized Clocks

Question from the Customer:

I am using two USB protocol analyzers, Beagle USB 12 Protocol Analyzer and Beagle USB 480 Protocol Analyzer. It looks like the clocks are out of sync between the two analyzers. My device receives data on one USB port, processes the data, and sends it on the other USB port. That the clocks are not synchronized makes it difficult to analyze the data - it looks like the device is sending data before it receives data to process.

Is there a way to synchronize the clocks between two Data Center Software sessions? Are there other analyzers I should consider?

Response from Technical Support:

Thanks for your question! The multiple point analysis of a USB system is extremely helpful for many development scenarios. A common example is the hub, where traffic is sent between the hub and the host, as well as between the hub and the device. In this scenario, clock drift prevents an accurate correlation of captured data from two different analyzers.

Our Solution for Synchronizing Clocks

Synchronizing capture events, start, trigger, and stop, on multiple analyzers can be difficult to accomplish. This feature is not supported by using the Beagle USB 480 analyzer or the Beagle USB 12 analyzer; however, this can be achieved by using a pair of the Beagle USB 5000 v2 Protocol Analyzer - Ultimate Edition.

How the Beagle Cross-Analyzer Sync Option Works

The Multi-Analyzer Synchronization feature on the Ultimate edition solves the challenges that are posed by multiple point analysis. With this option, you can easily and reliably monitor both sides of a USB hub, or any number of points in a USB system. Two HDMI ports on the back of the Beagle USB 5000 v2 analyzer allow two or more analyzers to synchronize their capture timestamps, as well as their capture start, capture trigger, and capture stop events.


Diagram of Hub with two Beagles Protocols and USB devices set up for synchronized data captures.

The Cross-Analyzer Sync Option is automatically enabled when two or more Beagle USB 5000 v2 analyzers, with this option licensed, are connected via their back panel HDMI ports. For more information about this feature, please refer to the section Cross-Analyzer Sync in the Beagle Protocol Analyzer User Manual.

For an example of using this feature, please refer to our knowledge base  Hub Latency Calculation using Beagle 5000 Analyzer.   This article describes how to set up the hub, the target device, target host, and analysis computer with two Beagle 5000 v2 analyzers. The example uses a USB 3.0 4-Port SIIG hub, and a SuperSpeed flash stick. The instructions can be modified for other devices.

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

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