| 摘要 |
PURPOSE:To surely recognize a transition state at a transmission side by providing an audible tone generating means detecting the transition state of the transmission side and generating an audible tone when the state is transited from the state that the transmission side makes data communication with the reception side into the state other than the data communication. CONSTITUTION:When its own station is in the data reception state, and when the opposite station of the sender side is transited to the talking state from the data sending state by a will for desiring the talking with its own station, the carrier from the opposite station is lost. The loss of the carrier is detected by a state transition detection circuit 6 and the information based on the detection is outputted from a state transition detection circuit 6 to a central control circuit 7. The central control circuit 7 drives an audible frequency generating circuit 8 in response to the output information from the state transition detection circuit 6, the output of the audible frequency generating circuit 8 is inputted to a speaker circuit 9 and transduced into an audible tone by a speaker 10. The operator at the reception side sensing the audible tone switches the state from the data reception state into the talking state to apply talking with the opposite station of the sender side.
|
