Bridging "grounds" on Zero Delay USB encoders

[bimm25e]

So Im going to be putting 2 of these in a NAOMI cabinet setup for 6 button fighters.  I already have 1 in place and it works great the other is in the mail.  My problem is that the 1p and 2p controls share a common ground, and i'll need to use the same "ground" for both of the USB controllers.  Does anyone know if  this is going to cause a problem?

[JDFan]

The grounds are all shared on each unit anyway (they have separate connection points but are all connected internally) and ground is ground so doesn't really matter if they share or are separate locations as long as there is a ground to complete the circuit when the button is pressed. So shouldn't be a problem !

[bimm25e]

Cool thanks,

I was just concerned because these devices dont use the USB ground, they only use the R,G,W,B cables and there is no pin utilized for the PC ground.  This made me worry that the return lines werent actually a "ground" but a different type of return circuit that shared some similaraties to a true ground.

[SavannahLion]

USB ground is one of the pins, not the outer shield of the plug.

USB specs require the outer jacket to be tied down only at the host. This is (I think) to prevent ground loops from occurring. One of the four wires is the true ground and as long as you follow standard wiring you should be OK.

I would tie one ground to one controller or the other, not both. Or split each harness as appropriate. I don't see a ground loop being a problem here (I'm no expert) because you're not dealing with high speed signaling or analog but chasing down an irksome loop is tiresome at best.