Ratoc Systems CBU2, User Manual, Page: 23 / 32

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4. Connecting a USB device
4-1. Self-power device/Bus-power device
There are two kinds of USB devices:
1.Self-power device:
This type of USB device gets power necessary to work itself through an outlet.
2.Bus-power device:
This type of USB device gets power necessary to work itself through an USB cable.
Each USB device of this type has its own current necessary to work itself. The maximum
current is 500mA. Here is an example.(Contact your device manufacturer for other devices)
Device Manufacurer Model name consumption current
•Mouse Microsoft IntelliMouse 100mA
•ImageScanner Cannon FB636U/630U 500mA
•CompactFlash Reader RATOC CF03U
100mA
•SmartMedia Reader RATOC SMA03U 100mA
4-2. Connecting a Bus-powered type of USB device to the CBU2
The CBU2 has two USB ports and these ports can provide 300mA in total. If you
connect our AC Adapter(Solf Separately) to the CBU2U, the two ports can provide
500mA at each port. If you connect a Bus-powered type of USB device of which
cunsumption current is over 300mA, you need to use the AC Adapter(Sold Seperately.
Refer to Chapter 8 for purchase information). You don’t need to purchase it if you connect
a Bus-powered type of USB device of which consumption current is less than 300mA.
Here is an example.
•If you connect FB636U/630U made by Cannon described above, its consumption current
exceed 300mA. Therefore, you need to use the AC Adapter to provide 500mA.
•If you connect CF03U and SMA03U simultaneously, their consumtion current is 200mA
in total. Therefore, you don’t need to use the AC Adapter. You can use them without
the AC Adapter.