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DAT 160 USB
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USB configuration Guide Setting up a USB network
7.3 Setting up a USB network
USB is very user friendly. The interface automatically assigns addresses to
devices; you simply need to connect a USB device to a USB port on a system
using a USB cable. If you have many USB devices or need to place a device
away from your system, you may place up to a maximum of five USB hubs
between the device and host system and connect them with additional cables.
If you are using a high-speed (USB 2.0) device, make sure that the USB host at
the system and all the hubs between the device and host support high-speed
(USB 2.0) transfer.
When using a bulk transfer device, such as a tape drive, do not use other USB
devices that will place restrictions on the USB bandwidth available to the bulk
transfer device.
If several USB device requiring large amounts of the USB network bandwidth
are to operate simultaneously, an additional host must be added to the system.
Each device must then be placed into the separate networks starting at the
different hosts. An additional host is typically a new USB HBA, which plugs into
the host system’s PCI slot, creating a new USB host that resides on the network.
I
If several USB adapters are placed into a system, demands on the
bandwidth of the system bus will constrain the USB devices’ perfor-
mance.
Always use USB logo-ed components in your USB network. This is the
best and easiest method to ensure reliable operation.
7.4 USB cables
USB cables are available in a variety of lengths. The maximum cable length is
5 meters. If you need to place a USB device further than 5 meters from the
system, you must use a hub.
Do not use USB cable extenders or couples. These are not recognized or
approved by the USB organization. The USB specification does not allow their
use and they are likely to reduce the reliability of the USB network or cause it
not to work completely.
Internal and external USB devices use the same USB cables.