| 摘要 |
PROBLEM TO BE SOLVED: To acquire an ID number so that the ID numbers of a plurality of slave machines differ. SOLUTION: When optical information signals are to be transmitted and received by the half-duplex optical communication system between a master machine 20 and the plurality of slave machines 40, one slave machine out of the plurality of slave machines generates an ID number in random number, one slave machine transmits an optical line usage request signal having the ID number to the master machine when it receives an optical line empty signal from the master machine, the master machine receives the optical line use request signal from one slave machine and transmits an optical line use permission signal having the ID number of only one slave machine that is detected from the optical line use request signals to the plurality of slave machines, and further the plurality of slave machines detect the ID number of one slave machine given to the optical line use permission signal from the master machine. Thus, only the slave machine that matches the ID number of one slave machine is allowed to annul the ID number that has been acquired and to use a random number for updating the ID number, when the ID number of another slave machine other than one slave machine coincides with that of one slave machine. |
