A device is disclosed that includes a master controller, a process chamber, a local controller, a switch, and a data storage. The process chamber is configured to generate a data according to a EUV light generation process. The local controller is coupled to the master controller and configured to control the process chamber. The switch is coupled between the master controller and the local controller, wherein the switch is configured to provide paths for the local controller to communicate with the master controller. The data storage directly connected to the local controller and configured to store the data. The local controller communicates directly with the data storage.