USB 2 or higher.

athena only responds to questions or if tagged in a comment, when ever you see the mention of her in the editor

I should chime in here. Both the question and Synthiam Support are incorrect. The question doesn't apply to the EZB because it does not have USB. The EZB has UART, which you connect to a UART<->USB adapter. That means the UART<-> USB adapter you purchase will determine the USB version. You decide what USB adapter to purchase; it has nothing to do with the EZB.

So choose a USB<->UART adapter that meets the requirements of your PC (USB 2 or 3 or C or what ever you need).

Here's the manual from EZ-Robot's website: https://www.ez-robot.com/learn-robotics-serial-usb-connectivity-ezb-smart-robot-controller.html

Thanks for your reply.

I did not know that Athena only replies to questions not conversations? My bad! I have also read the manual on USB connection before asking. My USB <-> UART adapter communicates fine for connecting the EZB V4/2 to the PC (at 921600). It is connected to the PC through a USB A 2.0 plug. My question( hope its not dumb). Would it make any difference if the USB <-> UART adapter had a USB 3.0 plug and connected to a USB 3.0 plug on PC? Hope I made this clear.

It’ll make no difference for what kind of usb uart adapter