Redundant, multitasking industrial controllers with synchronized data tables
US6411857B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | May 3, 1999 |
| Grant date | Jun 25, 2002 |
| Priority date | — |
| Expiry date | May 3, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/2097
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.