| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain an optical spatial communication device which prevents the incorrect acknowledgement about the cause of cutting in communication. <P>SOLUTION: When the communication is disconnected according to a certain cause in S3, it moves to S4. In S4, the level of receiving light is judged whether it is changed suddenly or not and when the receiving light is changed gradually, it moves to S5 and it is judged that the cutting of communication is caused by bad weather and an elapsed history is preserved in S6. Then it moves to the process in S7. When the level of receiving light is judged so that it is changed suddenly in S4 while the deviating amount of optical axis and the level of reception of light are dropped at the same time in S8, it is judged that it is instantaneous cutting due to obstacles in S9, and the elapse history is recorded together with a time in S10 and it moves to the process in S7. When the light receiving level is not deteriorated together with the change of deviating amount of optical axis upon change of the receiving optical level in S8, it is judged in S11 that the deviation of optical axis is due to gust, earthquake or the like and the elapse history is preserved in S12 together with the time and, thereafter, the alarm of abnormality is transmitted to the manager of a network in S13. <P>COPYRIGHT: (C)2008,JPO&INPIT |
