Script to force detection of peripherals in USB hubs?

Discussion in 'macOS' started by uncleMonty, May 31, 2013.

  1. uncleMonty macrumors regular

    Joined:
    Jun 8, 2012
    #1
    When I boot up, I have to unplug and plug in a hub, sometimes a few times, before my keyboard is recognized. Here's the set-up (it's on my MacBook Air, 10.7): on one USB port I have a Kanex DualRole, which is a combination USB 3.0 hub and an ethernet adaptor. (It was pricey, but exactly what I needed.) One of the things plugged into that USB 3.0 hub is a cheap Belkin USB 2 hub, for peripherals that don't need the bandwidth. And my external keyboard is plugged into that hub. So it goes: MBA --> Kanex DualRole --> Belkin USB 2 hub --> keyboard.

    When I boot up, the keyboard is not recognized. Kanex support have told me the following: "the DualRole acts as a USB hub Host and by adding the Belkin hub it will not be detected during the boot process, since now you have 2 hosts, and only the primary Hub host connected to MacBook Air will be detected." So I unplug the Belkin from the Kanex a couple of times, unplug the keyboard from the Belkin, plug everything back in, and after two or three times it usually works. But it's a pain in the neck!

    I (obviously) have no idea how it all works, but would it be possible to write a script that could make OS X force any hubs to query all of its inputs recursively so as to detect whatever is there?

    Thank you!
     
  2. Bear macrumors G3

    Joined:
    Jul 23, 2002
    Location:
    Sol III - Terra
    #2
    You have one or more bad USB hubs or cables.

    Or it could be a USB power issue - are both hubs powered? If not that could be causing the issue.

    I suggest you look at getting a powered USB 3.0 hub that has enough ports so you don't need to daisy chain hubs. And buy a USB to Ethernet adapter.
     
  3. uncleMonty thread starter macrumors regular

    Joined:
    Jun 8, 2012
    #3
    I *have* a USB to Ethernet adaptor, it's the DualRole. It takes ethernet and three USB 3.0 inputs and sends them all into one USB port. It works great once the connection tree is detected.

    I don't think it's a cable issue, I've tested with other cables. Both hubs are USB-powered. The Belkin and attached keyboard draw much less power than the Kanex and USB 3 port are rated for. (So do the other things plugged into the Kanex.)

    If you read what Kanex sent me, this is how they expect it to work, even with all components functioning properly. Hence my question of whether it's possible for OS X to send a "probe" of some sort through the hubs to "wake up" the connection.

    USB 3 hubs with many ports are still pretty expensive. Most peripherals don't need much bandwidth - I need several slots just for audio software license keys.

     
  4. KrisLord macrumors 6502a

    Joined:
    Sep 12, 2008
    Location:
    Northumberland, UK
    #4
    Does everything work ok if the hubs are both directly connected to the mac when you boot? ( rather than they daisy chain you have now)
     
  5. uncleMonty thread starter macrumors regular

    Joined:
    Jun 8, 2012
    #5
    Good question! Yes it does.
     
  6. Bear macrumors G3

    Joined:
    Jul 23, 2002
    Location:
    Sol III - Terra
    #6
    I wonder if you would have the same issue with USB hubs with external power supplies.
     

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