Patent ID: 7248679

Claim:
A Private Branch Exchange (PBX) apparatus for transmitting and receiving CID (Caller ID) comprising: an Analog Trunk Convergency (ATC) circuit for converging with an exchange in the PBX connected to the exchange; a Subscriber Line Convergency (SLC) circuit for transmitting CID and/or data by converging with a subscriber line connected to each port; a control circuit for controlling a CID service for the analog trunk and the subscriber line circuits; a data path control circuit for controlling data transmission through a data path between the ATC circuit and the SLC circuit; a CID service circuit, the CID service circuit including a CID and signal detecting circuit and a CID and signal transmitting circuit that each perform digital signal processing on the CIDs and signals; a signal transmitting/detecting circuit for performing signal transmitting and/or detecting through the data path; and a switching circuit for connecting the data path between the CID service circuit, and the ATC circuit and the SLC circuit, and for selectively switching the data path between the signal transmitting/detecting circuit and the CID service circuit.