| 摘要 |
PURPOSE:To realize the optical transceiver module provided with a loopback function to avoid a faulty terminal equipment in terminal equipments of a token ring optical LAN. CONSTITUTION:The module is provided with a changeover circuit 10 implementing a loopback function. When a terminal equipment is faulty, a control signal LBEN is set to a high level, gates 17, 19 are opened and gates 18, 20 are closed. A transmission signal TD given to an input terminal 22 is returned to its own reception circuit via a buffer 11, the gate 17 and an output buffer 16. Moreover, the optical signal from the transmission medium is once photoelectric-converted by a light receiving element 14, and inputted to a driver 12 via an amplifier 15 and the gate 19, converted into an optical signal by a light emitting element 13 and returned to the transmission medium. The module is operated at a faster speed than the case with an optical switch in use and the module is configurated inexpensively. |
