Patents by Inventor Dale H. Schultz

Dale H. Schultz has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • System and method for determining whether to transmit command to control computer by checking status of enable indicator associated with variable identified in the command
    Patent number: 5561770
    Abstract: A secure front-end communication system which couples a plurality of actively redundant process control computers to a computer network. The system includes a front end computer which is capable of establishing time limited communication contracts with one or more computer entity on the computer network. Each time limited communication contract is based upon an acceptable response to the transmission of an unpredicable signal from the front end computer, such as an encrypted transformation of a psuedo-random number generated by the front end computer. A security table is used to identify the network entities that are permitted to send write command messages to the process control computers to which the front end computer is connected. The front end computer also includes at least one permissive table which is used to determined whether a write command message from the network entity should be transmitted to the process control computer for which the message was intended.
    Type: Grant
    Filed: February 21, 1995
    Date of Patent: October 1, 1996
    Assignee: The Dow Chemical Company
    Inventors: Ronny P. de Bruijn, Leonardus A. van Weele, Marc L. K. Verboven, Roger R. Vermeire, Oscar E. Schulze, Brian G. Bell, Dale H. Schultz
  • Intelligent process control communication system and method having capability to time align corresponding data sets
    Patent number: 5519603
    Abstract: An intelligent front-end communication system which is interposed between a plurality of actively redundant process control computers and a computer network. The intelligent front end communication system includes at least one front end computer which is coupled to the computer network, and a serial communication interface which is coupled between the actively redundant process control computers and the front end computer. The serial communication interface transmits sequential sets of dynamic data from the actively redundant process control computers to the front end computer. The front end computer includes a plurality of reflective or shadow memory buffers for storing and time aligning corresponding sets of dynamic data which are asynchronously received from the serial communication interface.
    Type: Grant
    Filed: July 12, 1994
    Date of Patent: May 21, 1996
    Assignee: The Dow Chemical Company
    Inventors: James D. Allbery, Jr., Peter A. Troisi, Susan J. Johnson, James H. Cullen, Richard L. Butler, James P. Ferreira, Joseph Ellison, Stanley R. Nunn, Chiman L. Patel, James E. Uban, Dale H. Schultz
  • Secure communication system for re-establishing time limited communication between first and second computers before communication time period expiration using new random number
    Patent number: 5428745
    Abstract: A secure front-end communication system which couples a plurality of actively redundant process control computers to a computer network. The system includes a front end computer which is capable of establishing time limited communication contracts with one or more computer entity on the computer network. Each time limited communication contract is based upon an acceptable response to the transmission of an unpredicable signal from the front end computer, such as an encrypted transformation of a psuedo-random number generated by the front end computer. A security table is used to identify the network entities that are permitted to send write command messages to the process control computers to which the front end computer is connected. The front end computer also includes at least one permissive table which is used to determined whether a write command message from the network entity should be transmitted to the process control computer for which the message was intended.
    Type: Grant
    Filed: July 25, 1994
    Date of Patent: June 27, 1995
    Assignees: Dow Benelux N.V., The Dow Chemical Company
    Inventors: Ronny P. de Bruijn, Marc L. K. Verboven, Leonardus A. van Weele, Roger R. Vermeire, Oscar E. Schulze, Dale H. Schultz, Brian G. Bell