| 摘要 |
PURPOSE:To perform a control according to the level of a fault by branching the transmitted light of an optical transceiver to apply photoelectric conversion and outputting a fault notice when the number of times of the output continuing time exceeds the maximum packet length is beyond the specified number of times. CONSTITUTION:An optical signal 1 transmitted from an optical transceiver 13 by the control of a main body controller 14 is sent out to a network 2 through an optical distributor 6 and also, a part of it is inputted to and photoelectric-transferred at a receiving circuit 7. The electrical signal is inputted to a packet transmission time timer 8 and the measurement of a transmission time is started to count and when it is exceeded a regulated maximum packet length, an overflow signal is outputted and the number of time of an overflow is counted at a counter circuit 10. Also, the overflow signal is inputted to the main body controller 14 through a fault notice circuit 11 and performs a procedure to recover a fault in an internal circuit and when it is recovered, a normal sequence is executed. When the fault is not recovered and the counter circuit 10 counts a regulated number of time, a power cut-off circuit 9 cuts off a power source. Thus, it is possible to control a system corresponding with the level of the fault. |
