After a power outage, communications or equipment failure the AMI system returns to its normal operating state. The AMI meter retains data and continues to measure a customer’s power usage during communications failures. After a communications failure is repaired the AMI system transmits its stored data and resumes a normal communication schedule. If present, data aggregators may also retain some portion of data. Equipment failures should be detectable by system components that are aware of the absence of expected data. Failed equipment has the ability to be replaced and restored to the same state as prior to the failure. Outages will be logged but will have no other permanent effects upon the system. Two types of system outages are envisioned:
• Single-point equipment failure
• Wide-area outage (blackout)
Restoration after a wide-area outage must not overwhelm the communication system. The system should communicate planned outages to all involved actors (i.e. there may be “planned failures”). The AMI system shall attempt to classify the failure cause to optimize the recovery response.