GE 97916 GE High Speed USB 2.0 Stackable 7-Port Hub - Manual (Page 6)

IV. Power Mode Setting
There are two power mode options for the USB 2.0 7-Port Hub.
The first is self-power mode (recommended), which requires the use of
the AC power adapter. In this mode, a maximum of five (5)
high-powered USB devices may be connected to the hub at one time. If
more than five high-powered devices are connected, you will notice a
decrease in performance. (An additional hub is considered a
high-powered device.)
The second is bus-power mode, which does NOT require the use of the
AC power adapter. In this mode, the hub is provided with 500 milliamps
for all 7 ports. This should be adequate for mice, keyboards, and other
low power devices. If you are not sure or if device performance is poor,
use the AC adapter.
When using the AC power adapter, make sure the plug is properly
connected to a standard electrical outlet. Surge protection is
recommended.
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