| 摘要 |
PURPOSE:To attain suitable processing by adding a line interruption detecting function to a calling circuit of a communication device with automatic dial function to give an alarm if the line is interrupted at calling. CONSTITUTION:The line interruption detecting circuit 10 checking the connecting state of the line before the dialing from a dial circuit 2 is provided in the communication device with automatic dial function, and an alarm 11 is issued when the line interruption is detected to regulate the calling operation. Further, a line interruption detecting ineffective circuit 12 making the connection of the line interruption detecting circuit 10 ineffective and starting the dial circuit 2 is provided when the connecting state of the line is normal. Thus, when the connecting state of the lines L1, L2 is normal as the result of checking, the connection of the line interruption detecting circuit 10 is made ineffective for starting. |
