Icron USB Extenders

USB Extenders
How far away from a host can a peripheral be located?

The maximum cable length is 5 meters. Anything longer starts to cause problems due to propagation delays. Even if you violated the spec, it literally wouldn't get you very far. Assuming worst-case delay times, a full speed device at the bottom of 5 hubs and cables has a timeout margin of 280ps. Reducing this margin to 0ps would only give you an extra 5cm, which is hardly worth the trouble.

Special products have been developed to overcome the distance limitation of USB 1.1 and 2.0 by using local and remote devices at the host and peripheral ends. With these devices, USB connections up to 50M over CAT5 Copper or up to 10KM or over fiber are now possible. Icron was the first company to develop USB Extenders for USB 2.0

See illustration below

USB 2.0 Extender Products are available from a variety of manufacturers with these specifications typical:

• Plug and play support for USB 1.1 (low-speed, full-speed) and USB 2.0 highspeed
devices operating up to 480Mb/s.
• Support for all major operating systems including Windows, MAC-OS, Linux and Sun.
• Four USB ports provided at device side remote extender (REX).
• Powered at both the local extender (LEX) and remote extender (REX) modules.
• REX USB ports support high powered (500mA) devices.