| 摘要 |
PURPOSE:To attain data transmission even if no driver exists in an automobile by detecting a call signal to bring an automobile telephone set into off-hook state. CONSTITUTION:A radio transmission/reception section 1 outputs a call tone to a reception signal line (b). A call tone detection circuit 5 detects the call tone and outputs an H level to an OR circuit 6. Then the OR circuit 6 outputs H level to a hook signal line (d) to set the device to the off-hook state. Then the transmission/reception section 1 receives an off-hook signal and transmits/ receives data with a base station, then transmits an operating signal (e) representing the under-operation to a control section 2 and stops the call tone transmitted to the signal line (b). Thus, even when no driver exists in the automobile, the data is transmitted. |
