Patents by Inventor Mark A. Flood

Mark A. Flood 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).

  • Patent number: 6760634
    Abstract: A method and apparatus are disclosed for performing timely execution of periodic tasks in a redundant control system. A secondary controller in the redundant system receives a wakeup time array having at least one wakeup time element corresponding to a periodic task as well as a current time value from a primary controller, and schedules a run time for the periodic task at switchover based on the wakeup time element and the current time value from the primary control module. The secondary controller may further receive a task instance corresponding to the periodic task from the primary control module, and schedule a run time for the periodic task at switchover based on the task instance. In addition, the secondary controller may schedule a run time for the periodic task at switchover based on a default period associated with the periodic task, if no task instance and no wakeup time element were received corresponding to the periodic task.
    Type: Grant
    Filed: January 17, 2001
    Date of Patent: July 6, 2004
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: William Cook, Mark Flood
  • Publication number: 20020095221
    Abstract: A method and apparatus are disclosed for performing timely execution of periodic tasks in a redundant control system. A secondary controller in the redundant system receives a wakeup time array having at least one wakeup time element corresponding to a period task as well as a current time value from a primary controller, and schedules a run time for the periodic task at switchover based on the wakeup time element and the current time value from the primary control module. The secondary controller may further receive a task instance corresponding to the periodic task from the primary control module, and schedule a run time for the periodic task at switchover based on the task instance. In addition, the secondary controller may schedule a run time for the periodic task at switchover based on a default period associated with the periodic task, if no task instance and no wakeup time element were received corresponding to the periodic task.
    Type: Application
    Filed: January 17, 2001
    Publication date: July 18, 2002
    Inventors: William Cook, Mark Flood
  • Patent number: 6411857
    Abstract: An industrial control system employs a primary and secondary controller each having a processor and at least one I/O data table. Updating of the secondary processor's I/O data table is performed prior to the same data being transmitted to the controlled process. This eliminates possible retrogressive control at the time of switch-over of control from the primary industrial controller to the secondary industrial controller. Additional I/O data tables may be provided in each of the primary and secondary industrial controllers. In the case of the secondary industrial controller, this duplicate I/O data table temporarily holds data until the transmission is complete preventing the partial update of the working I/O data table of the secondary industrial controller. The duplicate I/O data table in the primary industrial controller allows simultaneous outputting of the I/O data transmitted to the controlled process without corruption while the user program of the primary industrial controller resumes execution.
    Type: Grant
    Filed: May 3, 1999
    Date of Patent: June 25, 2002
    Assignee: Rockwell Automation Technologies, Inc.
    Inventor: Mark A. Flood
  • Patent number: 5997166
    Abstract: A redundant controller employs two controller chassis having replaceable functional modules interconnected electrically within the chassis. System back up modules in the chassis coordinate the switching of control from a primary to a secondary chassis according to chassis redundancy state information of the chassis stored in the backup modules and module redundancy state information stored in the modules unique to the modules.
    Type: Grant
    Filed: June 18, 1997
    Date of Patent: December 7, 1999
    Assignee: Allen-Bradley Company, LLC
    Inventor: Mark A. Flood
  • Patent number: 5966300
    Abstract: A redundant industrial controller system has a primary controller backed up by a secondary controller and recovers from a power loss by analyzing the state memories of the controllers to reach a determination of which controller would best be suited to assume primary control status without resorting to arbitrary tie-breaking procedures or race conditions. The rules and their inputs are applied by both controllers which independently make the determination as to which controller should be the primary controller.
    Type: Grant
    Filed: June 18, 1997
    Date of Patent: October 12, 1999
    Assignee: Allen-Bradley Company, Inc.
    Inventors: Mark A. Flood, William B. Cook, Mark E. Taylor, Steven P. Richter
  • Patent number: 5966301
    Abstract: An industrial controller provides a primary controller and a redundant secondary controller and allows switchover between the controllers in the event of a failure in the primary controller. The process of qualification of the secondary controller in which its programming is made to match the primary controller may be inhibited to permit the secondary controller to maintain a clean version of an upgraded program executing on the primary controller. The clean program may be reverted to in the event an upgrading of the program in the primary controller is unsuccessful. Switchover is permitted even though the qualification of the secondary controller is not enabled.
    Type: Grant
    Filed: June 13, 1997
    Date of Patent: October 12, 1999
    Assignee: Allen-Bradley Company, LLC
    Inventors: William B. Cook, Mark A. Flood, Steven P. Richter, Mark E. Taylor, Bradley J. Bittorf
  • Patent number: 5966304
    Abstract: On-line upgrading of a primary industrial controller is provided through the use of a secondary industrial controller that may assume control of the process controlled by the primary industrial controller. A switch-over of control is orchestrated by a system back-up module that may detect removal of the functional components of the primary industrial controller to initiate the switch-over. Determination of removal of functional modules may be provided by a periodic polling of the functional components on the interconnecting communication link. The system back-up module designates one of the functional modules to poll the system back-up module so that complete coverage of removable components may be had.
    Type: Grant
    Filed: April 29, 1997
    Date of Patent: October 12, 1999
    Assignee: Allen-Bradley Company, LLC
    Inventors: William B. Cook, Mark A. Flood, Mark E. Taylor
  • Patent number: 5963448
    Abstract: A redundant controller employs connection-based messaging to ensure reliability and determinacy in communications. The need to close connections and reopen connections with a backup module when control switches from a primary controller to a secondary controller is eliminated by keeping the secondary controller updated as to the connections that have been opened and having the secondary controller assume the connection identification numbers of the primary controller upon switch-over.
    Type: Grant
    Filed: June 18, 1997
    Date of Patent: October 5, 1999
    Assignee: Allen-Bradley Company, LLC
    Inventors: Mark A. Flood, Mark E. Taylor
  • Patent number: 5933347
    Abstract: An industrial control system employs a primary and secondary controller each having a processor and an I/O data table. Updating of the secondary processor's I/O data table is accomplished synchronously with execution of the program in the primary processor at a particular point in the program. A tracking of changes in the I/O data table of the primary processor is used to transmit only changes in the I/O table to the secondary processor thereby avoiding undue interruption of the executing program while preserving synchronicity.
    Type: Grant
    Filed: June 13, 1997
    Date of Patent: August 3, 1999
    Assignee: Allen-Bradley Company LLC
    Inventors: William B. Cook, Mark A. Flood, Kenneth W. Batcher
  • Patent number: 5912814
    Abstract: An industrial control system employs a primary and secondary controller each having a processor and at least one I/O data table. Updating of the secondary processor's I/O data table is performed prior to the same data being transmitted to the controlled process. This eliminates possible retrogressive control at the time of switch-over of control from the primary industrial controller to the secondary industrial controller. Additional I/O data tables may be provided in each of the primary and secondary industrial controllers. In the case of the secondary industrial controller, this duplicate I/O data table temporarily holds data until the transmission is complete preventing the partial update of the working I/O data table of the secondary industrial controller. The duplicate I/O data table in the primary industrial controller allows simultaneous outputting of the I/O data transmitted to the controlled process without corruption while the user program of the primary industrial controller resumes execution.
    Type: Grant
    Filed: May 7, 1997
    Date of Patent: June 15, 1999
    Assignee: Allen-Bradley Company, LLC
    Inventor: Mark A. Flood
  • Patent number: 5777874
    Abstract: The present invention constitutes a data crossloading system for use with a programmable controller system having primary and secondary (or "back-up") systems each of which have redundant hardware components and have data structures associated with these components. The present invention further relates to the interconnection of the hardware components and to the processes for providing redundant data structures which enable a secondary or back-up system to rapidly and effectively assume control when a malfunction occurs in a primary control system. Both systems are connected via the same remote data links to common I/O racks which interface to sensing and output devices on the equipment being controlled.
    Type: Grant
    Filed: February 12, 1996
    Date of Patent: July 7, 1998
    Assignee: Allen-Bradley Company, Inc.
    Inventors: Mark A. Flood, Bradley J. Bittorf, William B. Cook, D. Alan Graham, Robert D. Law, David E. Mohnke, Robert R. Sepsi, Jack F. Toma
  • Patent number: 5627745
    Abstract: A method and apparatus for providing multitasking of a plurality of requests queued as a list in a single task of an industrial controller, each request including one or more separate segments. State information relating to each request being minimal at the end of each segment. The method processing the requests on a round-robin basis, interrupting each request only at the end of each segment so as to minimize the memory required to store the state information.
    Type: Grant
    Filed: May 3, 1995
    Date of Patent: May 6, 1997
    Assignee: Allen-Bradley Company, Inc.
    Inventor: Mark A. Flood
  • Patent number: 5428526
    Abstract: A communication module has a backplane interface circuit that enables the module to communicate with other components of the programmable controller, and has a network interface circuit which sends and receives messages via a serial communication link. A memory within the module stores a designation of a starting time, a designation of a length of a message repeat interval, and a file of message information. A clock circuit determines when the starting time occurs and thereafter determines the expiration of each successive occurrence of the message repeat period. A control mechanism responds to the clock circuit determining an occurrence of the starting time or determining an expiration of a message repeat interval, by operating network interface circuit to transmit a message, that contains the message information, over the serial communication link.
    Type: Grant
    Filed: February 3, 1993
    Date of Patent: June 27, 1995
    Inventors: Mark A. Flood, Clay T. White
  • Patent number: 5287548
    Abstract: A programmable controller governs the operation of a piece of equipment by executing machine language instructions compiled from a ladder diagram type control program. The control program as stored in the controller includes not only compiled machine language instructions, but also a tokenized version of the source code from which certain machine language instructions were compiled. The source code is provided only for those portions of the machine language program which cannot be easily decompiled to produce the corresponding source code. This program storage facilitates subsequent editing of the stored program via a terminal connected to the programmable controller. During the editing process, the original ladder diagram can be reconstructed from a combination of the machine language instructions and the tokenized version of the source code. In doing so, the machine language instructions, which have a one-to-one correspondence with the source code instructions, are decompiled using conventional techniques.
    Type: Grant
    Filed: February 29, 1988
    Date of Patent: February 15, 1994
    Assignee: Allen-Bradley Company, Inc.
    Inventors: Mark A. Flood, Michael D. Kalan, Charles M. Rischar, Robert R. Sepsi, Jack F. Toma
  • Patent number: 5193189
    Abstract: A programmable controller for operating a machine to perform programmed functions allows the user to allocate the amount of processing time to be devoted to a machine control program and to user defined background tasks. The allocation is defined by an entry stored in one of several locations in a data table. Each occurrence of a timed interrupt steps the operating system through the data table. When the operating system accesses the location at which the entry is stored, the machine control program is assigned as lower execution priority than any background tasks to be executed. When the last storage location of the data table is accessed, the user control program is restored to a higher execution priority than the background tasks before initiating another stepping sequence through the data table.
    Type: Grant
    Filed: December 9, 1991
    Date of Patent: March 9, 1993
    Assignee: Allen-Bradley Company, Inc.
    Inventors: Mark A. Flood, Michael D. Kalan, Peter N. Preis, Alden L. Peterson, II
  • Patent number: 4937777
    Abstract: A programmable controller for operating a machine to carry out programmed functions includes a plurality of program processors. Each of the program processors is operable to execute simultaneously a different user control program that directs the operation of the machine to perform specific functions. Each of the program processors includes a memory for storing the user control programs and function chart data. The function chart data comprises a series of descriptor files each of which contain an identification of a user control program to execute, a transition condition that indicates when the execution of that user control program is to terminate, and which descriptor file is to be processed next as well as the program processors to process it. A mechanism is also provided to enable the program processors to execute other programs in as background tasks without adversely affecting the execution of the control programs.
    Type: Grant
    Filed: October 7, 1987
    Date of Patent: June 26, 1990
    Assignee: Allen-Bradley Company, Inc.
    Inventors: Mark A. Flood, Michael D. Kalan, Peter N. Preis, Alden L. Peterson
  • Patent number: 4876664
    Abstract: A programmable controller suitable for operating a machine to carry out a plurality of programmed functions includes a plurality of program processors each being operable to execute simultaneously a different control program that directs the programmable controller to operate the machine to perform specific functions. Each of the processors includes a memory having areas for receiving different priority level messages. Each area has an addressable location corresponding to each module in the controller that can send messages. A message may be an executable command or a pointer to an address block containing the message or message access parameters.
    Type: Grant
    Filed: August 26, 1987
    Date of Patent: October 24, 1989
    Assignee: Allen-Bradley Company, Inc.
    Inventors: Bradley J. Bittorf, Mark A. Flood, Michael D. Kalan, Robert R. Sepsi
  • Patent number: 4829297
    Abstract: In a communication network wherein a master station periodically polls a number of remote stations to determine whether or not each remote station has data to transmit to the master, each of the remote stations is assigned to one two groups. One of the groups is designated as priority stations which commonly have very urgent data for the master station. The group of non-priority stations is sequentially polled for messages to be sent to the master station. The polling of the group of non-priority stations is periodically interrupted so that the master station may poll each of the stations in the priority group to determine if they have messages to send. Upon the completion of the polling of the priority stations, the polling of the non-priority stations is resumed. Periodically a time period occurs for inactive stations to join one of the two groups of stations on the network.
    Type: Grant
    Filed: May 8, 1987
    Date of Patent: May 9, 1989
    Assignee: Allen-Bradley Company, Inc.
    Inventors: Gregory R. S. Ilg, Lester A. Jones, Mark A. Flood
  • Patent number: 4521871
    Abstract: An active programmable controller services I/O racks which contain circuits that interface with sensing devices and operating devices on a machine being controlled. A back-up programmable controller monitors this I/O data to maintain a current I/O image table in its memory. Other status data is coupled to the back-up controller from the active controller through a peer-to-peer communications link. If a malfunction occurs in the active controller, the back-up controller is signaled to switch to the active mode in which it assumes control of the operating devices on the machine being controlled.
    Type: Grant
    Filed: April 12, 1982
    Date of Patent: June 4, 1985
    Assignee: Allen-Bradley Company
    Inventors: Daniel J. Galdun, Raymond A. Grudowski, Mark A. Flood