A system and method for remotely monitoring andor controlling an apparatus and specifically for remotely monitoring andor controlling an alarm. A dielectric layer having a opening therein is formed on a semiconductor substrate. The semiconductor module is provided with a mode signal pin for receiving a mode signal for requesting performance of a diagnostic operation, as well as with a result output pin for outputting diagnostic results. The light diffusion passive reflectors which are mutually adjoining are disposed to contact with each other without a gap in between, and are disposed so that the light-emitting surface is continuously arranged.