| 摘要 |
PURPOSE:To prevent out of synchronism from occurring in a high-order equipment when a terminal equipment is connected or non-connected to an optical bus communication system by adjusting phases between the path of an optical switch. CONSTITUTION:For connecting the terminal equipment 6 to a T line 2, levels are divided into a phase adjusting level and a connection level which is to completely connect the terminal equipment 6 to the T line 2 after the phase is adjusted so as to drive the optical switch 41. First, a phase adjusting circuit 62 adjusts the phases until the sum of a signal from a first input terminal A, which has been synthesized in an output terminal (d) and an inverted phase adjusting signal becomes zero. When the adjustment of the phases completes, the phase adjusting circuit 62 outputs control voltages X and Y so that only a first path generated in an input terminal (c) and an output terminal (b), and a second path generated in the input terminal A and the output terminal (b) are generated. Even if the terminal equipment 6 is branched for the T2 line or disconnected (or connected or non-connected), instantaneous cut with respect to a high-order terminal equipment or a network terminal equipment is prevented from occurring. |
