Accton Technology USB204A - Manual (Page 4)

4
USB Hub
• Hubs can be daisy-chained up to 5 deep in series, or in any
combination that does not exceed 127 devices.
• Hubs are dual-powered devices. They can be powered via
the uplink connection (bus-powered), or by an optional
power supply (self-powered).
• When bus-powered, downstream ports support only “low-
power” devices, such as a mouse, keyboard or a self-
powered hub.
• When self-powered, downstream ports can support “high-
power” devices, such as a printer or a bus-powered hub.
Note: A USB204A must be self-powered by an optional power adapter
to daisy-chain to another hub that is only bus-powered.
Connect the Hub to the Host PC
The USB204A should be connected
directly a host PC’s USB port. The hub
only has to be plugged in to the host
USB connector to operate. Up to 4
other hubs can then be daisy-chained
in series from the first hub.
1. Prepare standard shielded 90W USB
cable with Type-A (upstream) and
Type-B (downstream) plugs on
each end. The maximum cable
length is 5 meters (16.4 feet).
2. Connect the Type-A end of the cable to the host PC’s USB
port and the Type-B end to the hub.
3. Check that the hub’s upstream port LED is green. If this LED
is red or off, then follow the advice in the section
“Troubleshooting” to diagnose the problem.
Connect Devices to the Hub
Before connecting devices to the hub,
check the USB interface requirements.
Devices can be “low-power” or “high-
power,” with “low-speed” or “full-
speed” signaling. The USB204A is a
high-power, full-speed device. Refer to
instructions supplied with each USB
device for their individual operation.
1. Prepare standard 90W USB cable
with Type-A (upstream) and Type-B
(downstream) plugs on each end.
Low-Speed Devices: Shielded or unshielded 90W USB cable
Full-Speed Devices: Shielded 90W USB cable
Cable Length: Maximum 3 m (9.8 ft) for unshielded cable
Maximum 5 m (16.4 ft) for shielded cable