Design of usb extender over cat5?

Are you after Slow Speed, Full Speed or High Speed.

It gets harder as you go faster.

something like this?

Martin

What's the max of usb 1.1? 12 Mbps is what we need at most.

this?

That's one of them. Wonder what's in those black boxes.

this?

Can't be that much, given how small those boxes are.

this?

Magik. Whatever you do, dont't let the magik smoke out

Martin

this?

The idea is we build something like that ourselves, I'm trying to find out what's involved in this usb cat5/6 usb process.

this?

I hope what ever you find, you will be will to share. :-)

this?

Probably some differential signal drivers/transceivers.

With the number of hits google has (

I would think you would not need to build your own. Just buy one of them and take the case off.

Design and construction takes time, this way its done and proven. Looks cheap too.

Unless you have a special reason to understand whats inside.

don

I'd like to know what's inside and what it does to see if they are worth their money ;)

I can't find a lot in terms of user experience as well. If they just work, we may consider just getting some of them although they're somewhat expensive (we need something dirt cheap that works otherwise we may need to look for other options).

this?

Working on the theory that it might contain a single IC I googled for variations on "USB extender". I didn't find any IC product listings, datasheets or app notes though I havn't looked very hard.

It seems to me that the main issue with extending USB is that it uses half duplex bidirectional data on one twisted pair, followed by staying within the timing requirements

Here is a patent for a USB extender

It's for 480Mbps USB over optical fibre but is probably relevant to copper as well.

The descrption section mentions sending a "not acknowledge" message to the host to prevent it timing out while waiting for a reply.

Bob

I noticed it's quite small and several consumer products seem to be the same device with some cosmetic changes.

extender

I wonder if those little boxes are really smart in terms of awareness of actual usb protocol. Do they play a role in terms of usb or are they just transparent thingies as far as usb is concerned. The fact that most of them strongly mention usb 1.1 and not usb 2.0 may indicate it's not totally transparent.

One of the product descriptions, of a product that looks remarkably similar to several other mentions this:

register with the USB bus. It is

segment only. Please consider

also be connected to an exclusive

The first sentence could also be explained by the fact that it is simply transparent at the usb level.

seems to be recomeneded in various usb fora

Martin

I suspect they are aware of the low levels of the USB protocol. The timing of USB is fast enough that you just can't send the signals hundreds of metres with no changes to the protocol itself and have it work... at least reliably. Implementing something like that today is little more than a USB microcontroller for the "smarts," so the parts count doesn't have to be all that high.

I suppose there _are_ some that are just level converters/differential converters; I certainly wouldn't expect them to work nearly as well.

You might try asking your question here:

-- Some pretty hard-core USB developers hang out there.

---Joel

see this mine solutions : coax version :

DIY :

non-powered version: http://193.189.160.28/seibert/HP/UsbEnh/UsbLongCable2.gif

& this I use also for powering a wifi Usb stick at the same time http://193.189.160.28/seibert/HP/UsbEnh/UsbLongCable.gif

-- Regards , SPAJKY ® mail addr. @ my site @

5y - "Tualatin OC-ed / BX-Slot1 / inaudible setup!"

this?

"Cat 5" and "cat 6" actually only refer to the wire itself. If all of the USB signals are one-way (i.e., nothing bidirectional - I don't know anything about the USB bus) then you've got 4 pairs to buffer any signals you want to, and they don't all have to be used as balanced pairs.

So, if there are few enough USB lines, and the inputs and outputs are distinct, then a couple of buffer chips should give you whatever you want. If there are bidirectional lines on the USB bus, then you'd need a little bit of direction-switching logic, but that shouldn't be rocket science. ;-)

Good Luck! Rich