Here at Opto we found a USB barcode scanner that emulated a HID (Human Interface Device - aka, a keyboard) and used the Node (and followed to the letter the instructions on the same page) here;
This gave us the barcode into the flow each time we scanned, from there, it was a matter of writing the Node-RED flow to do the job we needed.
Note. We also found a Bluetooth scanner that we could not get working with the groov EPIC.