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USB Hub for myRIO

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I am just wondering whether myRIO suppports a USB HUB.  If so, how many cameras can I plug on it simultaneously? I think a extra power supply for usb hub is indispensable, but what about anything else? Say, does the bandwidth of usb permit? 

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Accepted by topic author 张弋

This all depends on the data rate of the cameras you are connecting. Just like it is POSSIBLE to connect a bunch of cameras to an ethernet hub, if you add enough with sufficiently high data rates, you will fill up your bus and will eventually have to drop frames. You will need to determine the maximum number of cameras yourself based on the data rate of the cameras and the bus capacity of the USB interface. USB 2.0 can reach a theoretical rate of 480 Mb/s, however you will not reach that speed since you will have overhead. 

 

To calculate the data rate of your cameras, use (FPS) * (X_resolution) * (Y_resolution) * (Pixel_Depth (8-bit,10-bit,12-bit etc)). This will give you the absolute lowest data rate ignoring overhead. 

 

For example, an uncompressed 8-bit monochrome 1280x1024 resolution camera running at 30fps will generate 314.5728 Mb/s without compression. Using this camera, you will only be able to use one of these cameras on the bus without dropping frames.

 

If you are using a camera the pre-compresses to something like MJPEG, you will have to take that into account as well.

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Hello 

 

Do you think is possible to connect an ethernet camera through a USB adaptor (ethernet usb), to myRIO for a vision project?

 

Regards

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