| 摘要 |
PURPOSE:To enable to perform three types signals to deliver, by using two frequency signals with a simple constitution, through counting with the counter after the reception of N signal and through the discrimination to the three types of information depending on the level of rectified output. CONSTITUTION:A number of transmission stations (T1)...(Tn) and reception stations (R1)...(Rn) are connected on the delivery line, and the signals R and N are outputted with the control circuit. On the other hand, the transmission station and the reception station build in the counter respectively, and the counter is reset when the signal R is received and the counter starts counting when the signal N is received. Further, the level of the rectified output discriminates no signal, information corresponding to one frequency signal, and information corresponding to the coexistence of the signal in both frequencies. Thus, three types of signal transmission can be made by using two frequency signals with a simple constitution. |
