| 摘要 |
PURPOSE:To obtain information from many information sources with one slave machine by discriminating automatically a signal for pager serviced at various modulation speeds. CONSTITUTION:Only a signal having a preliminarily determined frequency band is amplified selectively by a front end 2 and is demodulated by a demodulating circuit 3. The change point of the digital signal is detected by a change point detecting circuit 4. At the leading of the signal of a reference signal source 5 which has the phase synchronization, the signal of the circuit 3 is read by a decoding circuit 6. The number of times of alternate and continuous read of high and low levels is counted by a counter 7. When the counted value reaches a preliminarily determined value, it is judged that the frequency of the signal source 5 is equal to the modulation speed of the digital signal of the circuit 3, and the following signal is read by the frequency of the signal source 5. Thus, information from many information sources are obtained by one slave machine. |
