The file name 40cdq offers little beyond what looks like a component series prefix, with no model number grade, device, brand or revision attached. It is a 55 KB PDF filed as a schematic, most likely a short reference document for a family of parts rather than a board diagram. Such sheets are handy when identifying a part removed from a board, checking its pinout or comparing members of a series. Any PDF viewer opens it; confirm the full marking on your component, because a series name alone does not fix the exact variant.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @cyberlanelectonik. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.