USB cable length?

[ijhutch]

Got the product, love the performance.

But...the usb cable is too short to reach from the top of my 21" monitor down to the floor where my computer sits. So two things:

First, are there any guidelines about using a USB extension cable with TrackIR2? In other words, can they be used, is there a maximum length, any specific ones to stay away from, etc.?

Second, as an improvement, can you make the cable longer? I would imagine this would be a relatively inexpensive modification that would benefit many future buyers.

Thanks.

* ijhutch *

P.S. "dazed"...I hooked it up, it comes with a cable, it works great. But the cable is relatively short. I simply need to put an extension USB cable on it (A-A) so that I can put my PC back under my desk. My first question has to do if there are any design constraints on using an extension cable or if there are any potential length restrictions. Capische?

[ December 17, 2003, 07:55 PM: Message edited by: ijhutch ]

[dazed]

Look in the box again if you are saying you have no extension cable at all. The TiR is supplied with an extension cable . At least the TiR 1 was.

EDIT:

"Q1: How long of a cable can I use to connect my device?
A1: In practice, the USB specification limits the length of a cable between full speed devices to 5 meters (a little under 16 feet 5 inches). For a low speed device the limit is 3 meters (9 feet 10 inches)."

from: http://www.usb.org/faq/ans5

Im sure the TiR is a high speed device. Somebody correct me if im wrong tho. I doubt it uses a "special" USB cable.
Hope that helps.

[ December 17, 2003, 08:28 PM: Message edited by: dazed ]

[Magic Man]

There is no extension USB cable with the TrackIR2 - a single, slightly longer molded cable only.

As to the question of extension cables. I use a 1.5m USB extension on mine and it works perfectly.

[ijhutch]

TrackIR2 is a USB 1.1 device. I believe that only USB 2.0 deviced are considered "high speed".

So, bottom line is that being a "low speed" (USB 1.1) device, it appears I am limited to "the limit is 3 meters (9 feet 10 inches)" of total length. I'll have to measure the length of the existing cord and then subtract it from 3 meters to arrive at the maximum extension length (I'm at work now so I can't do it). I'll edit this post after I figure it out just in case someone else needs this info in the future.

Thanks for the replies, dazed (good link) and Magic Man (good practical info).

* ijhutch *

[ December 18, 2003, 06:50 PM: Message edited by: ijhutch ]

[dazed]

quote:Originally posted by ijhutch:
TrackIR2 is a USB 1.1 device. I believe that only USB 2.0 deviced are considered "high speed". Ahh! Thanks for the correction on the "high speed" device. Sorry, What i meant was, is TiR a "Full speed" device? so you could use a 5 meter (16 feet 5 inch) cable?

"Q1: How fast is USB?
A1: High speed USB products have a design data rate of 480 Mb/s. Full speed USB devices signal at 12Mb/s, while low speed devices use a 1.5Mb/s subchannel."

[ijhutch]

TrackIR2 is a USB 1.1 Full Speed device (just got off the phone with NaturalPoint Tech Support). The cable that is built in with the unit (not detachable at the base) is 6 feet long.

The Tech Support guy has tried appending two 3 foot extensions before (so 12' total but with two sets of midline connections, not just one)and noticed that there was a slight degredation of performance. But this could be due to additional loss/resistance from having two sets of additional connectors and not just one.

He is forwarding my question (along with this data) to the Engineering department ("Jim"), who is supposed to respond to this thread by COB today.

BTW, they want mucho $$$ at the stores around me for USB extension cables. I have found that ebay has much better pricing for new cables.

* ijhutch *

[ December 19, 2003, 05:01 PM: Message edited by: ijhutch ]

[Fish44]

Don't know what the design specs say, but I'm using a 3m extension USB cable (�12 apprrox Maplin) and it works fine for me.

Have to re-connect each time i start my computer, but don't think that's a related problem.

Really should have a longer cable, probaqbly another meter added would be sufficient. This would add very little cost to the unit.

[AV8R]

Standard spec for USB1.1 and USB2.0 is 5 meters or 15 feet. However, there are powered USB1.1 16 foot extention booster cables that can drive as far as 75 feet daisy chained.

What they look like:
http://www.iogear.com/resources/280/Web ... 0Image.jpg

Website:
http://www.iogear.com/products/product.php?Item=G2LUB16

[ February 10, 2004, 09:38 PM: Message edited by: AV8R ]