I think I posted something about this a good while ago, but forgot to follow through.
I run two lasers with Lighburn (possibly getting a third soon), both are connected by USB to the same computer. I was running jobs on both machines. While machine one was running one job, I switched Lighburn over to machine 2 and tried to send the job to that laser, but a message came up saying the machine was busy. Machine one finished it’s job and I again tried to send the job to machine 2 (with it correctly selected on Lighburn) and it sent it to machine 1.
Both lasers are running Rudia controllers, looking at the previous post I was asked if the USB was serial or packet, I don’t have a clue.