Question about cameras.

[ThePoll100]

Hi everyone.

I have a quick question, is this just happening to me? 

If I connect both cameras to the same USB hub, I can see them in the OpenPNP settings and configure them, but I always get no image from one camera. For them to work, I have to connect each camera to a separate USB port on my computer. Is this normal and how it's supposed to be? 

Best regards.

[Kevin Bralten]

This is quite normal - raw video can use more than half the available USB port.

You should look if you can select a compressed format like "MJPG" in the camera settings panel. Although, even then, some cheap cameras always request a huge amount of bandwidth which blocks anything else using the port. 

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[Niels PA1DSP]

AFAIK yes. USB 2.0 can only support the data for one camera, so you need separate interfaces for two cameras. 

Combining two USB 2.0 cameras with a USB 3.0 hub and 3.0 port on the PC should work in theory.

Regards,

Niels.

On 25 Apr 2026, at 15:10, ThePoll100 <mat...@gmail.com> wrote:



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[cdh...@gmail.com]

Not to pile on – but yes!

 

I had a very difficult time getting my two (ELP) cameras to work reliably.  Two major issues:

• When the PC starts up, Windows (or the firmware) “Enumerates” (looks for) what things are connected to the USB hubs.  Unfortunately, these devices are not assigned unique names that OpenPnP can address.  So, if you change anything (add a thumb drive, move plugs) the cameras might not be there, or they might be reversed.
• Bandwidth: You can typically only put one high-bandwidth device (e.g.: camera) per “USB Host Controller” and sometimes it’s not easy to figure out which host controls which ports (my PC has three).

 

Hope that helps.

 

Chuck Hackett

 

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