On Tuesday 01 April 2003 19:40, fsanta wrote:
Hi everyone
We have 8.1 up with a logitech webcam on the end of an astronomical telescope. It works fine with the computer next to the telescope but we want the computer 30 metres away. Is there any way I can do this with usb?
Thanks, Steve.
With a single USB cable you are out of luck. The USB design is limited to about 4 to 5 meters per cable. This is due to the signal reflections in the cable, and what needs to be done to manage it (26ns delay to allow the signal to even out before the next is sent... that sort of thing). There are a few things you can do to work around it though... assuming you have a low speed device (which I believe a webcam could be classed as) you can link up a few powered USB hubs in serial... I think it's about 5 hubs plus the initial cable from the PC for the physical limit.. That would give you the 30 meters you want. Another choice would be to look at commercial solutions that provide Ethernet bridges with a USB unit at each end. Not a very cost effective solution though since these things tend to be a bit pricey. C.