Abstract: A method for installing embedded firmware is provided. The method includes generating one or more firmware file instances and generating one or more digital certificate instances that are separate instances from the firmware file instances. The method includes associating the one or more digital certificate instances with the one or more firmware file instances to facilitate updating signature-unaware modules with signature-aware firmware or to facilitate updating signature-aware modules with signature-unaware firmware.

Abstract: A method for installing embedded firmware is provided. The method includes generating one or more firmware file instances and generating one or more digital certificate instances that are separate instances from the firmware file instances. The method includes associating the one or more digital certificate instances with the one or more firmware file instances to facilitate updating signature-unaware modules with signature-aware firmware or to facilitate updating signature-aware modules with signature-unaware firmware.

Abstract: A method for installing embedded firmware is provided. The method includes generating one or more firmware file instances and generating one or more digital certificate instances that are separate instances from the firmware file instances. The method includes associating the one or more digital certificate instances with the one or more firmware file instances to facilitate updating signature-unaware modules with signature-aware firmware or to facilitate updating signature-aware modules with signature-unaware firmware.

Abstract: A method for installing embedded firmware is provided. The method includes generating one or more firmware file instances and generating one or more digital certificate instances that are separate instances from the firmware file instances. The method includes associating the one or more digital certificate instances with the one or more firmware file instances to facilitate updating signature-unaware modules with signature-aware firmware or to facilitate updating signature-aware modules with signature-unaware firmware.

Abstract: A method for installing embedded firmware is provided. The method includes generating one or more firmware file instances and generating one or more digital certificate instances that are separate instances from the firmware file instances. The method includes associating the one or more digital certificate instances with the one or more firmware file instances to facilitate updating signature-unaware modules with signature-aware firmware or to facilitate updating signature-aware modules with signature-unaware firmware.

Abstract: A method for installing embedded firmware is provided. The method includes generating one or more firmware file instances and generating one or more digital certificate instances that are separate instances from the firmware file instances. The method includes associating the one or more digital certificate instances with the one or more firmware file instances to facilitate updating signature-unaware modules with signature-aware firmware or to facilitate updating signature-aware modules with signature-unaware firmware.

Abstract: A method for installing embedded firmware is provided. The method includes generating one or more firmware file instances and generating one or more digital certificate instances that are separate instances from the firmware file instances. The method includes associating the one or more digital certificate instances with the one or more firmware file instances to facilitate updating signature-unaware modules with signature-aware firmware or to facilitate updating signature-aware modules with signature-unaware firmware.

Abstract: An industrial control system implementing a multi-tasking operating system employs a primary and secondary controller each having a processor and an I/O data table. The processors are configured to execute one or more priority ranked programs. A tracking of changes in the I/O data table of the primary processor is used to independently track changes to controller specific data that has been changed and program specific data that has been changed and to transmit controller specific data that has been changed by any program and program specific data that has been changed only for completed programs to the secondary processor.

Abstract: A method for installing embedded firmware is provided. The method includes generating one or more firmware file instances and generating one or more digital certificate instances that are separate instances from the firmware file instances. The method includes associating the one or more digital certificate instances with the one or more firmware file instances to facilitate updating signature-unaware modules with signature-aware firmware or to facilitate updating signature-aware modules with signature-unaware firmware.

Abstract: An industrial control system implementing a multi-tasking operating system employs a primary and secondary controller each having a processor and an I/O data table. The processors are configured to execute one or more priority ranked programs. A tracking of changes in the I/O data table of the primary processor is used to independently track changes to controller specific data that has been changed and program specific data that has been changed and to transmit controller specific data that has been changed by any program and program specific data that has been changed only for completed programs to the secondary processor.

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.

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.

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.

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.

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.

Abstract: A communication circuit sends asynchronous digital signals in parallel to an external device. A first parity circuit in the communication circuit computes a first bit which indicates the parity of the control signals. This first bit is sent to the external device. When the digital signals and the parity bit are received by the external device, a first control signal is produced when each of the received digital signals has the same logic level for a defined period of time. A second parity circuit produces a second control signal when a parity error is found in the received digital signals. An error signal is generated in response to the presence of both the first and second control signals.

Abstract: A machine is controlled by a system which has a pair of programmable controllers connected in tandem. One controller operates in the active mode governing the operation of the machine, while the other controller is in a backup mode able to assume control of the machine should the active controller fail. Each programmable controller has a backup module through which the two controllers are connected. In order to determine which controller is to be active upon power up, each backup module has an input means for receiving a first active mode request signal from another programmable controller. A means is provided to produce a tie breaker signal at one backup module which indicates that its programmable controller is to operate in the active mode when both programmable controllers simultaneously desire to operate in the active mode.

Abstract: The invention involves working on a pipeline which is subject to movements relative to a base such as ground, the deck of a floating barge, and the like. A rollable scaffold is frictionally coupled to the pipeline so that workers carried by the scaffold can move relative to the base and, therefore, become stationary relative to the pipeline. The scaffold carries a lift means for raising and lowering a pipe support positionable under the pipeline. The scaffold therefore allows the workers to work on the pipeline without being disturbed by the relative movements between the pipeline and the base.