Recently, users of Project54 have reported that the USB devices connected to their in-car computers at random would not power up correctly. Typically, a system reboot would solve the problem and power up the devices, but this situation is not ideal. The police officers using the Project54 application need all USB devices to consistently perform, and rebooting their computers is time consuming. Carol Perkins and I set up a diagnostic test in which 5 USB devices, including a GPS, wireless antenna, touch screen monitor, video adapter, and scanner, were set up in 5 different USB port configurations with a CoolGear USB hub. As shown in the figure below, two devices, the video adapter and the Symbol Scanner DS6707, had issues booting up. The Symbol Scanner did not power on 14% of the 50 trial runs. Of these 7 failures, twice the device booted initially, but eventually powered down without instruction. The figure below also shows that the power failures occurred while connected to 4 different ports, so we concluded that the reported problem was not due to any power allocation problems within the USB hub. When powered correctly, this scanner performs exceptionally well, so users will be asked to unplug and then replug the scanner when a power up is not successful. 

- Erika Swanson

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