Patent Number: 6,170,044

Title: Systems and methods for synchronizing redundant controllers with minimal control disruption

Abstract: There is disclosed a system and method for maintaining data coherency between a primary process controller operable to execute process control tasks and a backup process controller operable to replace the primary process controller upon failure, wherein the primary process controller cyclically executes the process control tasks during base control cycles having a period, T. The system comprises 1) a tracking circuit operable to detect changed data in a main memory in the primary process controller; 2) a data buffer for temporarily storing the changed data; and 3) data transfer circuitry for transferring the changed data in the data buffer to a backup memory in the backup process controller at least once during each base control cycle of the primary process controller, such that the transfer of changed data does not interfere with execution of the process control tasks.

Inventors: McLaughlin; Paul Francis (Hatfield, PA), Swanson; Norman Raymond (Doylestown, PA)

Assignee: Honeywell Inc.

International Classification: G05B 19/04 (20060101); G05B 19/042 (20060101); G05B 9/03 (20060101); G06F 012/00 ()

Expiration Date: 01/02/2018