PURPOSE: To transfer a calling to a designated terminal without changing the line state of a single telephone set by providing a communication means performing the data transmission and reception with a main device, a means notifying transfer object, and a means interpreting the notification of the transfer object on a main device.
CONSTITUTION: At the time of the transfer of the calling of a telephone line 101 from a single telephone set 113 to 114, a communication control circuit 105 performs the notification of the transfer object to a main device 108 when a switch 116 is depressed. A main device 108 holds the calling state of the telephone line 101 and sends the notification cutting the single telephone set 114 from a communication control circuit 103 to a single telephone set connecting device 111, and sends the notification connecting the single telephone set 114 to the single telephone set connection device 113 to the single telephone set connecting device 112. The single telephone set connecting device 112 sends the request signal for connection to the single telephone set 114, and detects the response signal at a state detection circuit 118. A communication control circuit 107 sends the response notification to the main device 108. The main device 108 notifies the connection request to the single telephone set device 112, connects the held telephone line 101 to a speech line 115. The single telephone set connecting device 112 connects the single telephone set 114 to the speech line.
ASAMI KAZUHIRO
ONO MASAO
