Arbitration method and system for redundant controllers, with output interlock and automatic switching capabilities

Abstract

A method of providing arbitration for redundant controllers is provided, which includes: providing logic for automatically determining which controller of redundant controllers is active controller, wherein outputs of the redundant controllers are electrically hardwired together and provided as input to a device; and providing first and second hardware arbitration components for first and second controllers of the redundant controllers, each hardware arbitration component ensuring that outputs of the respective controller are enabled only when the associated controller is active controller. The first and second hardware arbitration components are separate hardware components which communicate and cooperate as a distributed hardware interlock mechanism that ensures outputs of only one controller are enabled at a time. More particularly, the hardware arbitration components each include a hardware state machine to enable/disable outputs of the associated controller and ensure that outputs of only the active controller are enabled as input to the device.