Hi

I want to switch two usb hubs but before I want to know which is better, a RJ11-> USB or RJ45->USB ? The power being transmitted is about a 5 to 6 watts, and the data transmitted is for networking purpose, also for the length of the cable I may use a 15 metters long cable to switch the two hubs. Below is a scheme :

Scheme 1 :

USB Device <-> USB->RJ11 Hub <-> Cable 15 metters <-> RJ11->USB Hub <-> Computer

Scheme 2 :

USB Device <-> USB->RJ45 Hub <-> Cable 15 metters <-> RJ45->USB Hub <-> Computer

Regards

Something like power over ethernet?

At first glance without knowing the details of the project, the exact adapters you are using and how they are built I would say it doesn't matter.

What is the supply voltage? What type of wiring are you going to use for the 15 meter cable? You will need to make sure the voltage drop will not be greater then the min voltage required at the equipment end.

RJ11 i.e. phone line if using a manufactured cable may not be twisted pair. Not enough detail to provide much help.

and I am hungry to give more & more info about my project
First the usb device is a webcam for surveillance, the operating voltage is DC 5V+/-5% and the maximum power this device consume is between 5 to 6 watts but may consume less in hibernate mode. In term of performance I have no idea witch of the two cables are better, I am afreed to get troubles like interference or signal disruption if I made a wrong choice so better to ask first, also as we still talk about power, it seem RJ11 can't supply more than 300mw according to this thread a little googling

The link does not work for me.

You need 1.2 amps worst case. The voltage drop must be < 0.25 VDC which means the total resistance of the wiring must be < 0.21 ohms. So Basically you need to run 12ga wiring from the computer to power the webcam. You can run multiple cables of smaller ga and in this case you need two CAT 5 cables i.e. one for power and one for ground. You also might want to consider a remote AC-DC 5V power supply.

I've used USB cat 5 extenders successfully for a remote USB touch screen up to 150 ft successfully but I didn't have to worry about power.

Thank you for the reply, may I correct the link for you : http://forums.reprap.org/read.php?13,28822 Seem that this connection with cat 5 cables didn't work always, please watch what someone is traying to do with it but no luck http://www.youtube.com/watch?v=0y2ct3MhHwk

It seem that even ethernet cables are not the seem, someone suggests cat 5e cable instead of cat 5. To confirme ...

Not only voltage is important, but also timings, as USB devices must to answer each other in specified time, and signal traveling by 15 meters may arrive too late. Standard specify maximum 5 metres of cable length.

@michaelk:
This 150ft is just on simple cable or it has some equipment which regenerate signal?

A device similar to this:
http://www.cablestogo.com/product.as...1521&sku=29341

Is it the cable or the hub that should be cat5e ? or both ?

Yes. The device in the link posted is not a hub.

I never asked what you meant by hub in your original post.

I mean the switch, my webcam pluged directly to a computer didn't require external power supply, it get its power from the usb itself So the usb is playing two roles transfering data on one side and powering the required power to the cam from an other site. I which this may succeed as well with the rj45 connection. Some succeed in youtube to power and transfer their data or pda or mobile phone juste by pluging the device to usb->rj45 switch and so one. But I think it should be cat 5e to work that is why my latter question.

The device I posted is not a USB networking adapter, nor can it be plugged into a normal network switch.

The problem as already stated the max distance for USB is 5 meters and the camera requires the max amount of current USB can provide. I'm not sure how your project is related to PDAs or mobile devices.

Exactly, if I try just 10m usb cable it won't work but 5m it work. So and for that reason I want to use an ethernet cable instead to elevate the problem of maximum range.

The USB extender in the link provided will get you the distance desired for data but not power. For that I would suggest a remote power supply which will require a special adapter.

okay, thank you for the info.