Extending USB Range

Take a look at the faq on usb.org

The bottom line is that you're out of luck.

"Dan Rhodes" wrote in message news: snipped-for-privacy@posting.google.com...

Several parts to this. The signals are differential, but also bi-directional. There are very tight 'constraints' on the overall time taken for bus 'turn round' and signal delays. It is possible, by adding some 'glue logic', to implement a transciever, that uses a 'better' signalling standard, and extends the range to perhaps

200 feet, but beyond this the timings fall apart (a couple of commercial products exist to do this). Hence you can't go the sort of distance you need with a passive transceiver device. The commercial units that go further, instead behave as a single device 'hub', and talk unit-unit, then regenerate the USB bus at the far end. Remember that each USB device, itself needs to have an ID and drivers, so to build a DIY unit, will involve either using a standard chipset, and assuming that drivers will be available, or either using a 'trick' bodge to an existing hub chipset, or building your own devices, writing the drivers, and registering this as a USB device... Even on the commercial devices, many of the cheaper units, still have reliability problems. Look at units like the Icron ExtremeUSB devices. Some are available with bus lengths up to 500m, using multi-mode fibre optic cable ( 'EverGreen', alse do versions of these as their 'FireLINE' products - your length is longer than I have found any of the 'Cat5' based solutions to work reliably...). No solution is going to be cheap. As a completely 'lateral' solution, you could use a 'single board' industrial PC, at the remote end, to scan the USB device, and then send the data (depending on rate), over another medium (unfortunately, the length is such, that even ethernet, would require repeaters). A 'USB-RS232/422' converter device, would not normally do what you want. Most are only available as 'slave' devices, and the data rate required by USB, will bring the bus length supported down below the distance you require.

Best Wishes

In article , snipped-for-privacy@ttelmah.demon.co.uk mentioned...

No, it does not. Standard Ethernet, which is 10Base2, is 200 meters, or about 600 feet. That is over RG-58, and 10BaseT will also go that far. If you _must_ have the full 12 MB USB 1.1, then this won't work because standard Ethernet is 10 MB.

I can't figure out why people insist on using USB for longer distances, which is like trying to drive a nail with a screwdriver. Use the right tool for the job. Use Ethernet, and for that distance use a pair of media converters and run fiber most of the way.