| 摘要 |
A signal processing apparatus for subscriber circuits is disclosed which comprises a plurality of circuits each for extracting a signal corresponding to a.c. and d.c. signals flowing through each of a plurality of subscriber circuits, an analog multiplexing circuit connected to the output terminal of each of the plurality of extracting circuits, an analog-to-digital converter connected to the output terminal of the analog multiplexing circuit, and a signal processing circuit connected to the output terminal of the analog-to-digital converter and receiving successively and periodically a digital signal corresponding to the output signal of each of the extracting circuits for processing the digital signal to detect the state of each of the subscriber circuits, the reception of the digital signal being made by sending a selective signal to the analog multiplexing circuit.
|
