Abstract: A digital switching system connecting buses with incompatible protocols and a telephone answering system and private automatic branch exchange with integrated voice and textual message recording is disclosed. The digital switching system (10) in accordance with the invention permits a digital switching matrix (12) having an input bus and an output bus to connect information on the input bus selectively to information on the output bus in response to control signals applied to switches of the switching matrix. A plurality of information systems (18, 20 and 22) each having a different bus protocol are electrically connected to the input and output buses of the switching matrix to permit information transmitted on a conductor of any of the information buses to be received by another conductor of any of the information buses through the input bus, the switching matrix and the output bus. A host processor controls the plurality of information systems.

Abstract: A digital switching system (10) in accordance with the invention includes a digital switching matrix (12) having an input bus and output bus; a plurality of information systems (18, 20 and 22) with each information system having an information bus for transmitting and receiving information using a protocol which is different from a protocol used by the information bus of each of the other information systems with the information buses of the information systems being electrically connected to the input and output buses of the matrix to permit information transmitted on any of the information buses to be received by any of the information buses through the input bus, the switching matrix and the output bus; a host processor (34), for controlling the information systems with commands; and a control processor (16), for generating control signals controlling switching of switches of the digital switching matrix.

Abstract: An automatic line supervisor is disclosed for a telephone system having a line concentrator which converges a plurality of subscriber lines into a single output line to a telephone answering service (TAS) which is coupled to the concentrator by a telephone line with automatic ring down (ringing tie line). In order for the line to properly operate after the TAS has answered a subscriber call, and gone back on hook, the telephone concentrator must be disconnected from the ringing tie line and from the caller. In a first embodiment, the automatic line supervisor is an integral part of the concentrator and operates to make the requisite disconnection of the concentrator from the ringing tie line and the caller on a subscriber line by monitoring the tie line for appropriate audio tones, generating a control signal either in response to the presence of a dial tone for a particular time interval or in response to the absence of DTMF tones (dual tone multifrequency) for a particular time interval.

Abstract: A control system for enabling direct inward dialed telephone calls received on a single access line from a telephone central office to be answered with identity. The single access line is coupled at the telephone central office to a block of telephone numbers, and incoming calls to any of these numbers are connected to the access line and to an operator at a telephone answering location through the control system, and the number called is decoded by the control system. A DID line ("DID" stands for direct inward dial) on the interface is arranged in the input section of the control system and is coupled to the single access line that receives the telephone calls from the telephone central office. At least the last digit of the telephone number is decoded within the control system and a visual display of the decoded number is then provided for identifying the incoming call.