At&t Information Systems Inc.

Other

At&t Bell Laboratories

Bell Telephone Laboratories

George W Schramm

John B Sharp

Richard J Nici

David J Stelte

Hans George Mattes

Gerald S Soloway

David W Petr

John William Wesner, Jr

Emanuel J Fulcomer, Jr

Colonel Blake McDowell, Iii

Michael M Winseck, Jr

Vance E Poteat

Jeffrey Neumann

Victor Scott Borison

Richard P Marzec

David M Tutelman

A data transmission system that can controllably transmit data in three different modes between connected data devices. The first mode transmits data at a 64 Kbps rate. The second mode transmits data at a 56 Kbps rate plus control signals at an 8 Kbps rate. The third mode transmits data and control messages at a rate of up to 50 Kbps between connected terminals or other data devices. For all modes, the data is transmitted by inserting it one byte at a time into an information field of successive ones of cyclically reoccurring time multiplexed frames.

Multimode data communication system

A data communication method and circuitry which uses a compatible subset of a standard high level data link control (HDLC) protocol to control link level communication between a digital terminal and a switch. The use of the subset of HDLC protocol reduces the complexity of the digital terminal design while maintaining communication compatibility with a switch which uses either the standard HDLC protocol or the subset of HDLC protocol.

Data communication method and circuitry

There is disclosed a processor controlled digital communication device which accepts message commands from a communication system as part of a communication protocol. These command messages are stripped from the protocol and combined within the communication device to control signaling thereat. Multi-bit time separated information (I) fields are used together with a single bit signaling (S) field. The S field bits are compiled over several frames to become the command messages.

Digital communication station signaling control

There is disclosed a digital telephone having dual voice and data handling capability over a single communication line. Time separated information channels are used to transport the voice and data information between the terminal and the main processor. A separate signaling channel is shared between the two information channels and information on the signaling channel is accumulated for distribution to either the voice device or the data device in accordance with address information contained within the accumulated signaling channel message.

Digital dual channel communication terminal

A business transaction terminal for a credit authorization system or the like includes a microprocessor for receiving data from a magnetic card reader and a keyboard, automatically processing such data and transmitting it to a central data base for authorization of a proposed business transaction. The terminal receives back a response from the central data base which directs subsequent actions by the terminal user. Options are provided for receiving the response in a number of ways such as audible response, visual indicators and numeric displays. Options also permit the terminal to be operated in a hands free mode.

Terminal apparatus

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Oakhurst, NJ, United States of America

George W Schramm