Seems like it's going into some deep sleep mode. I have a user that keeps saying he has to restart the plotter frequently to print to it. It is setup as a network printer. I haven't been able to to catch it when it's happening, so in all possibility it could an issue with his computer, but since he says it works after he restart the plotter I'm giving him the benefit of the doubt that something is up with the plotter itself. I can't find anything in the Web UI to disable sleep. The manual said there is an option to increase the time to 240 sec from the default of 30 sec before it goes to sleep, but I'm not really sure that will help. He has been able to print to it while it has been sleeping so not even sure that is the issue.