PDA

View Full Version : Camera Serial Number Problem - PCI Express



jamiet@pent.com
November 6, 2007, 17:06:08
I am using the ActiveX contorl with the new USB 640x480 cameras. When I have the cameras hooked into an on-board USB port or a port on a PCI card, all is well. When I have on ehooked into a USB port on a PCI express card, the camera is seen but the serial number comes back as 0. This is true both with the ActiveX control AND in the SampleDemo app. Any insight would be helpful.

Also, I am using 8 of these cameras simultaneously and wondered if anyone knew how much bandwidth each camera requires on teh USB bus. I am using 640x480 30fps UYVY for each camera. Unfortunately I am only able to support 2 cameras per PCI card. If I use more than that, the fps goes way down. Each port should be full speed so I am a little confused.

Thanks!

Jamie

Stefan Geissler
November 6, 2007, 18:03:46
Hi Jamie,

The PCI express is another bus than the PCI bus, thus Windows seems to differ the cameras using the bus types. In fact, the hardware IDs are different. Therefore, while the camera is connected to the PCI Express, the standard Windows USB video driver is in use, that does not expose an interface for reading out the serial number. If the camera is connected to the PCI bus, then the The Imaging Source WDM driver is in use. (I suppose you have installed this driver...)

Solution: Connect the cameras to the PCI Express and install the The Imaging Source WDM driver from the CD ROM that came with your camera. (Or download it from http://www.theimagingsource.com).

Then you should be able to readout the serial number.

jamiet@pent.com
November 6, 2007, 19:38:29
I will try re-loading the drivers from the website.... but that is what I originally did.

Any insights into the bandwidth issue at all? I would have assumed that a PCi card that has 4 ports on the card would be able to handle 4 DFK21AU04 cameras running with the above mentioned parameters.

Thanks!

Jamie

Stefan Geissler
November 7, 2007, 09:51:44
Hi Jamie,

even if you have a PCI Express USB card, the USB 2.0 will not be faster then USB 2.0 on a PCI card. You should expect that 640*480 UYVY at 30 fps needs more than 50% of the USB 2.0 bandwidth. Thus you should use BY8 instead of UYVY, then you can connect two cameras at one USB controller and get a colored video at 30 fps. You should try this with IC Capture.

The USB card can handle 4 cameras (or more if a hub is connected), but the live video stream of all 4 cameras can not been started simultaneously. The bottleneck is the bandwidth that can be handled by one USB controller. I suppose on your USB card is only one controller.