| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical communication system for connecting between a key station and a plurality of slave stations by an optical fiber via an optical branching device, and for performing reception by previously setting photosensitivity in response to optical reception strength when the optical reception strength from the slave station can be estimated, and setting the photosensitivity to one of plural steps when the optical reception strength from the slave station cannot be estimated. <P>SOLUTION: The photosensitivity of a light receiving element is to be set in response to strength data of an optical signal written to an LLID table from the slave station when communication is to be performed to a specific slave station (T4 to T8). When the communication is to be performed to an unspecified slave station, an upward optical signal from a slave station (such as an adjacent slave station) whose upward optical signal is strong can be correctly received since the photosensitivity of the light receiving element is to be set to a lower level at a time point before receiving the upward optical signal from the slave station (T1). When the upward optical signal which cannot be correctly received caused by insufficiency in sensitivity is detected as present, next optical transmission from the slave station is to be waited after changing the photosensitivity of the light receiving element to a lower level since it will be known by an error check, detection of an optical level, etc (T9 to T11). <P>COPYRIGHT: (C)2006,JPO&NCIPI |
