Data communications system

• US 4,860,379 A
• Filed: 10/20/1988
• Issued: 08/22/1989
• Est. Priority Date: 05/18/1979
• Status: Expired due to Term

• Current Assignee: General Instrument Corporation (CommScope Holding Company, Inc.)
• Original Assignee: General Instrument Corporation (CommScope Holding Company, Inc.)
• Inventors: Schoeneberger, Carl F., Bundens, Allan B.
• Primary Examiner(s): Chin, Tommy P.
• Application Number:
  US07/262,245
• Time in Patent Office: 306 Days
• Field of Search: 358/84, 358/86, 455/2, 455/3, 455/4, 455/5, 455/6, 340/502, 340/504, 340/505, 340/533, 340/534, 340/825.52, 340/825.53, 340/825.54
• US Class Current: 725/24
• CPC Class Codes: H04N 2007/17372 the upstream transmission being initiated or timed by a signal from upstream of the user terminal
• CPC Class Codes: H04N 7/17363 at or near the user terminal
• CPC Class Codes: H04Q 9/14 Calling by using pulses

Abstract

A data communications system utilizes computer control at central and remote locations to provide general data acquisition and control functions as part of a cable television network. The data system includes a central data processor communicating with a plurality of remote data processors, each of which in turn interrogates, monitors and controls a plurality of groups of remote terminal unit. Each terminal unit includes a variety of security monitoring devices as well as other data generating apparatus useful in process control and data retrieval functions. Each terminal unit communicates with its remote data processor concerning the status of the security devices and receives commands from the remote data processor to carry out data acquisition and control functions including controlling access to the cable television network by the terminals. The remote data processors communicate with the terminal units utilizing both time and frequency division multiplexing in a frequency shift key mode. Communication between the remote data processor and the home terminals is preferably on the coaxial cable utilized for transmitting commercial programming for the television network. The central data processor includes a minicomputer interfacing with input/output devices and external data links. Each remote data processor includes a microcomputer having input/output devices attached thereto and interfacing between the minicomputer and the remote terminal units.

Claims

1. A communications system for remote data acquisition and control comprising;

a central data processing system, a plurality of remote data processing systems in communication with said central data processing system and a plurality of remote user terminals each in communication with one of said remote data processing sytems, wherein;

the central data processing system comprises first computer means for processing, storing and retrieving data, and first communication means having multiple channels for two-way data communication with each of said remote data processing systems;

said each remote processing system comprises second computer means for generating and processing data to monitor and control the operation of each of a group of said plurality of remote user terminals, said second computer means being programmed for generating control data to control the operation of each of said remote user terminals and processing response data from each of said remote user terminals to monitor the operation of said each of said remote user terminals, and second communication means for two-way data communication with said remote data processing system and with each of said group of said remote user terminals, including means for transmitting said control data to said each in said group of said remote user terminals and means for receiving said response data from said each in said group of said remote user terminals; and

each of said plurality of remote user terminals comprises means for receiving said control data from one of said remote data processing systems, means for generating response data in response to said control data and means for transmitting said response data to said one remote data processing system.

2. The system of claim 1 wherein said remote data processing systems control and monitor all routine operations of said remote user terminals, and the second computer means is further programmed for communicating with the central data processing system in response to special commands from the central data processing system.

3. The system of claim 2 wherein said second communication means each includes a frequency shift key means for communicating data between said remote data processing means and each of said remote user terminals in a frequency shift key mode.

4. The system of claim 2 wherein said response data is representative of a security status of said remote user terminal.

5. The system of claim 1 wherein said second computer means is further programmed for generating time division multiplexed (TDM) control data and processing TDM response data.

6. The system of claim 1 wherein said control data includes an identification number as a part of said control data, wherein said transmitting means simultaneously transmits said control data to a set of said remote user terminals responsive to said terminal identification number, and wherein said second computer means is further programmed for sequentially changing said terminal identification number to enable said transmitting means to transmit said control data to different sets of remote user terminals during sequential time intervals.

7. The system of claim 6 wherein said transmitting means transmits control data to said set of remote user terminals at a first frequency, and wherein said transmitting means of each of the remote user terminals in said set transmit response data to one of said receiving means of said remote data processing systems at a different frequency from said first frequency and from the frequencies of the response data of the other remote user terminals in said set.

8. The system of claim 1 wherein said receiving means of said second communication means comprises frequency means for receiving and processing frequency division multiplexed (FDM) response data.

9. The system of claim 8 wherein said frequency means comprises FDM receiver means for receiving FDM response data from a set of said remote user terminals, and differentiator means for separating the FDM response data by frequency for transmission to said second computer means.

10. The system of claim 9 wherein said remote user terminals are connected to said FDM receiver means in a plurality of groups, said set of terminals comprising a terminal in each group which is responsive to a common identification number, and wherein said FDM receiver means includes means for simultaneously receiving FDM data from said set of user terminals which have said common identification number.

11. The system of claim 1 wherein said response data is representative of an operating status of said remote user terminal.

12. The system of claim 1 wherein said first communications means comprises a radio frequency data link.

13. The system of claim 1 and further comprising television source means in communication with one of said remote data systems for transmitting television signals to the remote user terminals in communication with said remote data system, and wherein said second computer means of said remote data system is further programmed for generating control data to selectively enable and disable said user terminals to receive said television signals.

14. The communication system of claim 1 wherein said remote data processing systems control and monitor all routine operations of said remote user terminals, and the second computer means is further programmed for communicating with the central data processing system in response to nonroutine response data from the remote user terminals.

15. A communications system for remote data acquisition and control comprising:

a central data processing system, a plurality of remote data processing systems in communication with said central data processing system and a plurality of remote user terminals each in communication with one of said remote data processing systems, wherein;

the central data processing system comprises first computer means for processing, storing and retrieving data, and first communication means having multiple channels for two-way data communication with each of said remote data processing system, said first computer means being programmed for generating command data to control each said remote data processing system and processing interrupt data from each said remote data processing system, and said first communication means including means for transmitting said command data to each of said remote data processing systems and means for receiving said interrupt data from each remote data processing system;

each remote data processing system including second computer means for processing, storing and retrieving data, and second communication means for two-way data communication between said remote data processing system and each of a group of said remote user terminals, said second computer means being further programmed for generating control data to control the operation of each of a group of said remote user terminals, processing response data from each said remote user terminal to monitor the status of each said remote user terminal, and generating said interrupt data in response to response data from one of said remote user terminals indicative of a predetermined status of said one remote user terminal, said second communication means including means for receiving said data from said central data processing system, means for transmitting said interrupt data to said central data processing system, means for transmitting said control data to each of said group of remote user terminals and means for receiving said response data from each said remote user terminal;

each of said remote user terminals having means for receiving said control data from one of said remote data processing systems, means for generating said response data in response to said control data and means for transmitting said response data to one of said remote data processing systems.

16. A computer-operated data communications system for use in conjunction with a cable television distribution network having one or more television program sources and a plurality of remote cable television receivers communicating with said one or more sources over coaxial cable transmission lines, comprising:

a plurality of remote data terminal means for controlling and monitoring said plurality of remote cable television receivers, each of said terminal means being connected to one of said television receivers to control access of said one television receiver to said cable television distribution network;

a plurality of computerized remote data processing means for controlling and monitoring said remote data terminal means, each of said plurality of remote data processing means being in communication with a group of said remote data terminal means over the coaxial cable transmission lines used by said one or more television program sources to communicate with said remote television receivers;

each of said plurality of remote data processing means having primary communication means for transmitting and receiving multiplexed data to and from said plurality of remote data terminal means, for controlling access of said television receivers to the cable television distribution network and for receiving data representative of the operation of said television receivers including nonroutine data representative of abnormal operation of said television receivers; and

a computerized central data processing means in communication with each of said plurality of remote data processing means for controlling and monitoring said plurality of remote data processing means, said central data processing means including secondary communication means for receiving said nonroutine data and for transmitting said control data to said plurality of remote data processing means, said control data further including data responsive to said nonroutine data.

17. The system of claim 16 wherein said central data processing means communicates with said plurality of remote data processing means substantially only upon receiving said nonroutine data from the primary data processing means.

18. The system of claim 16 wherein said primary communication means comprises multiplexing means for transmitting time multiplexed to and receiving frequency multiplexed data from said plurality of remote data terminal means.

19. The system of claim 16 wherein said primary communication means comprises time multiplexing means including transmitter means for transmitting said control data having a predetermined identification code to a set of remote data terminal means responsive to said predetermined identification code, said remote data processing means being programmed for sequentially changing said identification code, and frequency multiplexing means including receiver means for simultaneously receiving response data transmitted from each of said set of remote data terminal means at a different frequency.

20. The system of claim 16 wherein said primary communication means includes a frequency shift key means for communicating with said plurality of remote terminal means in a frequency shift key mode.

21. A communications system for remote data acquisition and control comprising a data processing system and a plurality of remote user terminals each in communication with said data processing system over a single communication channel;

the data processing system comprising computer means for processing, storing and retrieving data, and communication means for time and frequency multiplexed communication between said computer means and each of said remote user terminals;

said computer means being programmed for generating control data for said remote user terminals, said control data having an identification code representative of a common set of said remote user terminals, and processing response data from said remote user terminals;

said communication means including means for transmitting said control data at a single frequency to said set of remote user terminals simultaneously over said single channel, means for receiving said response data at a plurality of frequencies from said set of remote user terminals simultaneously over said single channel, said receiving means including frequency-responsive means for processing said response data to identify the response data associated with each of said remote user terminals at which said response data was transmitted to said communication means;

each of said remote user terminals comprising means for receiving said control data from said data processing system, terminal address code-responsive means for generating said response data, and means for transmitting said response data to said data processing system at a frequency unique with respect to the frequencies of the response data of the other terminals in said set;

whereby said data processing system transmits said control data simultaneously to said common set of remote user terminals and receives said response data simultaneously from said set of remote user terminals.

22. The system of claim 21 wherein said communication means includes means for time division multiplexed (TDM) communications with a plurality of sets of said remote user terminals, and said computer means is further programmed for sequentially changing said identification number of said control data to enable said transmitting means of said communication means to transmit said control data to a different set of said remote user terminals during sequential time intervals.

23. The system of claim 21 wherein said frequency-responsive means of said communication means comprises a plurality of receiver means for receiving the response data according to frequency.

24. The system of claim 21 wherein said communication means of said data processing system and said receiving and transmitting means of said remote user terminals include frequency shift key means for communicating data between said data processing system and each of said remote user terminals in a frequency shift key mode.

25. A communications systems for remote data acquisitions and control comprising a central data processing system and a plurality of sets of remote user terminals, each set being in time and frequency multiplexed data communication with said central data processing system, wherein:

the central data processing system includes time division multiplexing means for sequentially processing data for each of said sets of remote user terminals, means for transmitting said control data simultaneously at one frequency to one of said set of remote user terminals, and means for receiving response data at a plurality of frequencies simultaneously from said set of remote user terminals, said central data processing system being programmed for generating control data for each set of said remote user terminals and for sequentially processing said response data from said set of remote user terminals;

said each of said remote user terminals in each set including means for receiving said control data from said central data processing system, means for generating response data for processing by said central data processing system and means for transmitting said response data to said central data processing system at a frequency unique with respect to the frequencies of the response data of the other remote user terminals in said set.