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.
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. Data structure information in the primary system is specially crossloaded to the secondary system so that when a malfunction occurs that shuts down the primary system, the secondary system can begin execution of the same control programs and input and output the same data to the same I/O racks based on up to date data from the primary system. The crossloading of the data is accomplished through the use of special backup modules in both the primary and secondary (backup) control systems connected by a high speed communications link. Communications take place through the use of program utilities which establish a tightly coupled communications network between the primary and secondary systems. Additionally, on-line editing is enabled in stages so that when either control system can not properly execute the edit it is rejected. This system insures that edits can not take place in the primary system without being concurrently implemented in the secondary system.
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.