METHOD AND SYSTEM FOR INSPECTING RING SHAPED OPTICAL NETWORK LINE FOR DATA COMMUNICATION AMONG PLURALITY OF IN-VEHICLE NETWORK SUBSCRIBERS

摘要

PROBLEM TO BE SOLVED: To provide an inspection technology for a fault that may be caused in an optical network line. SOLUTION: One network subscriber 1 executes a master function and has optical network lines 8 and other communication lines 7. The communication lines 7 take a star type structure, the master network subscriber 1 is placed in the center of the star structure and directly connected to all other network subscribers 2-6 via the communication lines 7. The master network subscriber 1 transmits a start signal to the network subscribers 2-6 via the commination lines 7, the network subscribers 2-6 transmit an affirmative reply of the start signal to the master network subscriber 1 via the communication lines 7. After the transmission of the start signal, the master network subscriber 1 transmits an initial setting signal via the optical network lines 8, the master network subscriber 1 can confirms its normal operation when the master network subscriber 1 can receive a signal corresponding to a specified signal through the optical network lines 8 within a prescribed time.