Abstract: The present invention provides a low cost implemented optical add/drop device suitable for application in a WDM based optical subscriber network that assigns a unique wavelength to each subscriber, which uses an inexpensive optical tap coupler device and an usual optical fiber Bragg grating, simplifying the configuration and manufacturing process, while having relatively high quality performance. The optical add/drop device according to the present invention uses a combination of an optical tap coupler and an optical fiber Bragg grating, instead of a combination of an optical circulator and an optical fiber Bragg grating. Therefore, the cost is 10 times lower than an add/drop device adopting the optical circulator, and the configuration is simple. In addition, the implementation is very easy because the already-existing mature components can be utilized as they are.

Abstract: The present invention provides a serial bus type configuration recognition and alarm apparatus for a system having a plurality of various boards. The apparatus of the present invention includes a plurality of first transmission units, a second transmission unit and a recognition unit. The first transmission units report board IDentifications (IDs) and board failure status information through a first serial bus. The second transmission unit is connected to the first transmission units to report the board IDs, the board failure status information and an ID thereof. The recognition unit is connected to the second transmission unit to ascertain the configuration and failure status of the boards and report received board IDs and board failure status to a terminal.