Systems and methods for minimizing peer-to-peer control disruption during fail-over in a system of redundant controllers

For use in a process facility having a plurality of process systems that produce process data, wherein the process data are gathered byprocess controllers associated with the process systems and are exchanged by the process controllers via a network, a method of operating a redundant process controller associated with a first selected process system, the redundant process controller comprising a primary process controller, a secondary process controller and a data redundancy controller and capable of receiving process data from at least one remote process controller and intermittently transferring the received process data to the first selected process system, a method comprising the steps of:

• storing the received process data in the primary process controller and storing a copy of the received process data in the secondary process controller;
• transmitting the received process data from the primary process controller to the first selected process system;
• monitoring message traffic into and out of the primary process controller to detect a failure of the primary process controller to communicate with at least one process system;
• and
• upon detection of a failure of the primary process controller to communicate with the at least one process system, transmitting the received process data to the first selected process system from the secondary process controller in lieu of said primary process controller,
• wherein the data redundancy controller monitors process data stored in the primary process controller and modifies process data stored in the secondary process controller to make the process data in the secondary process controller substantially identical to the process data stored in the primary process controller.

A process control system comprising:

• a plurality of process systems capable of producing process data;
• and
• a plurality of process controllers associated with plurality of process systems, wherein said plurality of process controllers gather said process data and exchange said process data via a network, wherein at least one of said plurality of process controllers is a redundant process controller associated with a first selected process system said redundant process controller comprising:
• a primary process controller having a first memory capable of storing process data received from at least one remote process controller, wherein said primary process controller is operative to transmit said received process data to said first selected process system;
• a secondary process controller having a second memory capable of storing said received process data, wherein said secondary process controller monitors message traffic into and out of said primary process controller to detect a failure of said primary process controller to communicate with at least one process system and is operative, upon detection of a failure of said primary process controller to communicate with said at least one process system, to transmit to said first selected process system said process data stored in said second memory in lieu of said primary process controller;
• and
• a data redundancy controller, wherein said data redundancy controller monitors data stored in said first memory and modifies data stored in said second memory to make said second memory data substantially identical to said first memory data.