Failover, a simple and efficient redundancy scheme based on software and hardware, is available for the ISaGRAF 5 Runtime. Once enabled, the failover will duplicate all resources attached to a configuration. The duplicated resources will then run on a redundant controller, which is completely independent of the original controller. The original controller is called the primary target and the redundant controller is called the secondary target. Upon failure of the primary target controller, the secondary, having received regular updates of the real-time database from the primary, assumes control within one scan cycle.