| 摘要 |
PURPOSE:To reduce the probability of causing pseudo the acquisition of synchronism by making same codes consecutive for hook information bits added to an identification header when a counter-ground hooking state is changed and making codes alternative in other cases. CONSTITUTION:A hook information bit deciding circuit 7 decides a hook information bit 107 assigned to an identification header 101 inputted from an identification header detection circuit 2 and a hook information bit state transition monitoring circuit 8 monitors whether or not the hook information bit 107 applies state transition based on the decision. Only when a counter-hooking state of the information bit 107 is changed, the same code is consecutively transmitted to represent the change state and codes are transmitted alternately in other cases. Thus, the probability of causing the pseudo acquisition of synchronism is reduced when frame synchronization is taken by the identification header 101. |
