Maximum USB Length and Canon 20D?

[dwdallam]

Does anyone know the maximum length extension you can use with the Canon 20D using the latest USB? I think the USB cable you get with the 20D is like 2 feet long, which makes it pretty useless. I also know that with USB 2x and "fast" connections, such as printers and scanners, you can go a maximum of 16 feet, with slower devices, such as keyboards and mice, the max is I think 10 feet.

Thanks

[61Dynamic]

The USB spec is 5 meters (16 feet as you mentioned) but I've seen non-powered USB cords extended to 100' and still work (doesn't work with all devices... based on wether or not the device is powered (sometimes), not the data transfer rate).

Most computer stores sell USB cable extenders of varying length. The only way to know if more than 2' will work with the 20D is to try it.

[dwdallam]

The USB spec is 5 meters (16 feet as you mentioned) but I've seen non-powered USB cords extended to 100' and still work (doesn't work with all devices... based on wether or not the device is powered (sometimes), not the data transfer rate).

Most computer stores sell USB cable extenders of varying length. The only way to know if more than 2' will work with the 20D is to try it.
[a href=\"index.php?act=findpost&pid=55998\"][{POST_SNAPBACK}][/a]

Well, I had a ten foot USB cord I purched at the local computer store, which was discontinuing retail sales. It seems taht the cord I got was one from a long time ago, and had teh crappy old style clip connectors, instead of the friction force type now available. I camera was dropping its connection about every 5 minutes. I'd have to plug and unplug the old cable which the canon supplied cable to get it to reappear on the devices configuration panel in windows.

Where I live, no one had a 10 foot cord. I bought a six foot that I'm using tomorrow. If that fixes the problem, tehn I'll order online a longer one. It would be nice to have 15 feet to play with.

[Andrew Larkin]

The timing in USB signals is critical to its reliable operation.  The specs give you a maximum of 5 metres because of these timing issues - poor quality cables can introduce signal timing issues that reduce this maximum distance.

The only way to extend beyond the 5 metre limit is to regenerate the signal.  This is done by a USB hub or similar device.

USB extender cables basically have a built-in one-port hub to do this signal regeneration.

Even doing the signal regeneration, there is a maximum "depth" of the hub chaining of 5 devices.

That means that even if you use powered hubs with 5 metre connecting cables, the maximum distance you can cover is 25 metres.

Reality will be something less than this.

If you need to extend further than this, you have to use a different technology.

For example, there are fibre-optic USB extenders that claim distances of 10km.

Andrew

[dwdallam]

The timing in USB signals is critical to its reliable operation.  The specs give you a maximum of 5 metres because of these timing issues - poor quality cables can introduce signal timing issues that reduce this maximum distance.

The only way to extend beyond the 5 metre limit is to regenerate the signal.  This is done by a USB hub or similar device.

USB extender cables basically have a built-in one-port hub to do this signal regeneration.

Even doing the signal regeneration, there is a maximum "depth" of the hub chaining of 5 devices.

That means that even if you use powered hubs with 5 metre connecting cables, the maximum distance you can cover is 25 metres.

Reality will be something less than this.

If you need to extend further than this, you have to use a different technology.

For example, there are fibre-optic USB extenders that claim distances of 10km.

Andrew
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Thanks for that information. I actually have a bad motherboard. It seems that the secondary controller is having problems. I'm getting "unknown" device messages on one of my secondary USB onboard pin ports. Removing and reinstalling gives the same message. Disabling the secondary USB controller in the BIOS corrects the problem, but then the three internal USB pinports don't work.

Tonight I plugged my USB printer back in and got an "Unknown Device" message as well from my integrated and main USB port also. I unplugged it and replugged it and it worked, but the MB has USB controller problems it seems.

I'm hoping the camera didn't somehow fry it. The technician where I bought the MB said he didn't think that was the case. We'll see. I'm going to try it again after I get the new MB swapped out. What do you think?

[ayumisano]

The timing in USB signals is critical to its reliable operation.  The specs give you a maximum of 5 metres because of these timing issues - poor quality cables can introduce signal timing issues that reduce this maximum distance.

The only way to extend beyond the 5 metre limit is to regenerate the signal.  This is done by a USB hub or similar device.

USB extender cables basically have a built-in one-port hub to do this signal regeneration.

Even doing the signal regeneration, there is a maximum "depth" of the hub chaining of 5 devices.

That means that even if you use powered hubs with 5 metre connecting cables, the maximum distance you can cover is 25 metres.

Reality will be something less than this.

If you need to extend further than this, you have to use a different technology.

For example, there are fibre-optic USB extenders that claim distances of 10km.

Andrew
[a href=\"index.php?act=findpost&pid=56273\"][{POST_SNAPBACK}][/a]

I am interested in the fibre-optic USB extenders that claim distances of 10km (although I only need an extender of 500m). Do you know which company produces this and where I can buy it?

Will the signal be weakened after being extended for 500m?

Thank you very much for your help!