Wednesday, December 14, 2011

USB3 fit for machine vision?

USB cameras have never really been adopted for machine vision. Yes there are some products on the market – Lumenera seems to be leading the pack – but they’ve failed to break through. As I understand it, this is mainly due to the way USB tends to hog more CPU time than does FireWire or GigE, and because it’s difficult to have more than a single camera per PC.

Things seem different with USB3. This interface seems to be building a head of steam with vendors such as Point Grey, Ximea, and Basler all launching USB3 cameras.

What does that mean for we end-users? I think it means life just got a little more complicated. There I was, getting to grips with GigE, learning how to address the cameras (not as easy as the vendors would have you believe,) and now they expect me to try something else. And what does USB3 give that GigE doesn’t?

I’m not sure I know. Speeds are broadly comparable and cable lengths are plenty long enough for my industrial needs. One difference might be that USB3 supplies power, so I can save on a separate power supply. Yes, I could go PoE but that doesn’t really seem to have broken through, so camera choices are limited.

I don’t know about you, but I think I’ll hang back and watch how this all pans out.


Dany Longval said...

USB3 is actually much faster than Gige. Transmission sped is up to 5 Gbit/sec. High speed, high resolution sensors such as CMOSIS 4 megapixels, 180 fps sensor chokes Gige pretty rapidly but will run much faster on USB3.

Anonymous said...

Speed is the biggest thing, and better isochronous support than USB 2.0. Isochronous support means more hardware buffering a la FireWire, meaning less dependency on the CPU being free, which should address the biggest reason USB 2 sucks for machine vision.

Ron Mueller said...

Another nice detail of USB3: It supports a Master - Slave architecture, where one of the external devices can be the "Master". This means - one camera can be the Master and control the other cameras attached to the same processing unit.