USB or PS2 for long distances

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Gawd
Joined
Dec 24, 2004
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The USB keyboard in my theater is going to be a good 20 feet from the PC. It's an incredibly small unit, fits perfectly where I want it (beside the seat) and it's looks are perfect for a theater. I don't want to toss it and go wireless.

The low-speed USB spec for cable lenght is 10 feet. Leaves a couple choices, curious for input on which is the best way to go.

I can go: keyboard cable (4 foot) plugged into 6 foot extension (total 10 feet), plugged into a powered USB hub (acting as a repeater), then a 10 foot cord into the PC. Meets the spec, but a waste of a powered USB hub.

Or, I can plug the keyboard's USB cable into a USB to PS2 adapter, then use a PS2 extension cable to the back of the PC. Use two extensions back to back if needed. A lot neater job.

Problem is, USB cable specs are easy to find, but I can't find the max lenght for a PS2 cable run anywhere.

Anyone know that spec, make a recommendation on which way to go with this LAST issue before it goes live?

Thanks!
 
well my recomendation would be usb but ps2 might be able to take the distance but maybe not
 
I don't know where you looked up the usb spec, but I have several 16' usb cables that work perfectly. They are readily available from most stores, so I would assume that people use them successfully all the time.
 
Ok the real issue with USB cable length is the guage of the wire that is used. In general the short cables are made of higher gage wire (thinner wire) and can run a shorter distance than a higher guage wire so attaching short cables together is a bad idea.

Here is some info I pulled from a book I have:
28 Guage: 0.81m(2.66' feet)
26 Guage: 1.31m((4.3 feet)
24 Guage: 2.08m(6.82 feet)
22 Guage: 3.3m(10.93 feet)
20 Guage: 5.00m(16.40 feet)

I would say there is a good chance of this working without a problem using 20 Guage wire (or if you could find something with say 18 Guage wiring. As for using a hub as a repeater... It may or may not help because I'm not sure that the hub repeats the actual digital signal so much as gives each port 5v power but I don't have any concrete information on this subject.

Best of luck with your project.
 
The Bryophyte said:
I don't know where you looked up the usb spec, but I have several 16' usb cables that work perfectly. They are readily available from most stores, so I would assume that people use them successfully all the time.
Click to expand...

Got the USB spec right off the usb.org website. HIGH speed (2.0) is good for 16 feet. But LOW speed (1.1) is limited to 10 feet. The keyboard is a low speed device.

They also recommend using a powered hub in the middle as a sort of repeater, says you can do that up to 30 meters. I'd have to figure they're talking about a hub that conditions signals too (thanks Canon), not a cheap POS like most of them are.

I have a 16 foot extension here at work, think I'll borrow it and see if it works anyways. Won't hurt anything if not.

Thanks for all the answers!
 
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