Hello Bernie On 26 Aug 2002 at 9:56, Bernie Berg wrote:
> > I have tested two "Dexxa" webcams (compatible with Logitec Quickcam > > Express), on the same USB bus. I set it up to take alternating snap > > shots from each camera. This works well and could be expanded to more > > camera's. > > That should work, but at 85 cams this could get kinda messy. How fast > can you alternate? I ran 1 image every 15 seconds per camera, with 2 camera's, which was enough for my requirement. There is a very real finite limit to the bandwidth on USB. I don't think this will scale to 85 cams on one bus. You could try and split them over say 4 buses and aim for a refresh rate of 1 pic per 5 seconds per camera. It will depend on the resolution of each picture. > If I used the wireless x10 cams with usb adapters I don't think I would > reach 15m. The problem I think I would have with the x10's are that one > receiver controls a number of cams (3 I think) and you can switch > between them (at least that is how the windows software works), but I > need them to all act independently. I've tried contacting x10 to ask > some technical questions but the hold times are too long and they don't > reply to emails. I don't see all of those wireless controllers expanding to 85 camera's. (Do they have enough independent channels and enough range?) I am going to try "thin client" boxes on a network, each with say 4 cameras - the limitation being the USB cable lengths. 2 Boxes and 8 camera's should meet my requirement. But each box will need power and a place to live so this probably won't scale to 85 cameras either. Your installation will be quite large, have you talked to any "professional" companies? I would hate to be running around a site chasing 85 "domestic quality" web cams when one or another of them keeps dying for unknown reasons and the supplier does not answer the phone! Regards Ian --------------------------------------------------------------------- Ian Forbes ZSD http://www.zsd.co.za Office: +27 21 683-1388 Fax: +27 21 674-1106 Snail Mail: P.O. Box 46827, Glosderry, 7702, South Africa ---------------------------------------------------------------------