a human-machine interface module, mounted on a panel of the AC/DC power supply or controller, a front of the human-machine interface module having a liquid crystal display;

a film, located in front of the human-machine interface module and attached to the panel of the AC/DC power supply or controller, wherein the film has a transparent window corresponding to the liquid crystal display, the window is located on the liquid crystal display, the film further has a status indication region adjacent to an outer side of the window, and the status indication region is marked with a plurality of different status messages;

wherein when in use, the liquid crystal display displays a light spot corresponding to one of the status messages, allowing a user to directly read the corresponding status message through the location of the light spot.