| 摘要 |
PURPOSE:To eliminate a factor to the deterioration in the processing ability of the software, by constituting a monitor circuit having two kinds of signal recognizing time and its switching circuit with the hardware so as to decrease the number of interfaces. CONSTITUTION:In receiving a command transmitting an SZ signal F1 from a controller to an opposite exhange at a signal transceiver 102 via a lead 203, the F1 signal SZ is transmitted to the opposite exchange via a line 202 and applied to a double supplemental detecting circuit 104, which monitors the F1 signal from the opposite party via the line 202. In detecting an F2 signal PTS from the opposite party via the line 202 and the signal transceiver 102, the signal is applied to a device idle state detecting circuit 103, the double supplemental detecting circuit 104 and a signal recognizing time monitor circuit 105. The controller stops the transmission of the F1 signal. When the device idle state detecting circuit 103 detects the stop of the F2 signal at a lead 205, the circuit 103 discriminates that the device is busy, the F1+F2 signal is received and the stop of signal is detected, then it is discriminated as the device idle state. |
