Just to clearyfy......
At the beginning of my webcam adventures I had a problem using active usb cables 10 meters long , the pc went down with a warning that damage to the pc would happen and therefore the pc went down completely.
After I went back to the shop the gave me a new one as I was thinking the active usb cable was not ok,gues what.... the second cable hat the same problem.
So i went back to and buy a passive cable and put the usb cam more nearbye,no problems anymore.
If I change my configuration now i would do the following :
I would use passive cables up to the roof with them and at the end I would put a USB hub true the roofwindow, I would take a usb hup with at LEAST 1 ampere where the normal pc or laptop only gives 0.5 ampere.
If someone thinks this is the wrong way I would be happy to hear what would be the correct configuration,as I have plans to change my cam position to the roof to get a more wide vieuw ,but active usb cable are not an option for me anymore.
I want at about 15 meters to the roof position.
Cheers Chris