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USB2Test - problem in loopback test mode

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  • USB2Test - problem in loopback test mode


    using USB2Test I can successfully test USB 2.0 ports in benchmark mode but the loopback test mode fails right away if I check the box "Verify Data Transferred".

    With BIT 6 pro the USB tests pass, presumably because it is using USB2Test in benchmark mode?

    The more pressing question is how do I get loopback testing to work? I am using USB2 test plugs on USB 2 ports, so I doubt it's a hardware issue.

    Thanks in advance for your help.

    EDIT: I should add that I get 0 verification errors but a lot of transceiver errors when using loopback mode. Maybe I am interpreting those incorrectly?

  • #2
    A verify error means the high level application data sent to the USB loopback plug doesn't match the data received. These are actually pretty rare errors as there is a lower level checksum / re-transmission scheme in the USB protocol that should 'fix' most of these errors. But it doesn't sound like you are getting this error in any case.

    A transceiver error is more common. This can indicate a bad CRC check, data corruption and several other low level problems. More details are on this page,
    The #1 cause of transceiver errors is bad cables, long cables especially cause problems. But it can also be electrical interference, bad connectors, power problems, etc..