Patent ID: 8130084

Claim:
A computer program product comprising a non-transitory computer readable medium having a computer readable program, wherein the computer readable program, when executed in a rack-mounted data processing system comprising an alternating current power distribution and communication (ACPDC) controller and a powered element, causes the rack-mounted data processing system to: receive, by the powered element, a primary alternating current power signal with primary communication data and a redundant alternating current power signal with redundant communication data from the ACPDC controller; determining, by a primary controller in the powered element, whether the primary communication data is intended for the powered element; determining, by a redundant controller in the powered element, whether the redundant communication data is intended for the powered element; responsive to the primary communication data being for the powered element and the primary controller working properly, executing, by the primary controller in the powered element, a set of instructions included in the primary communication data in the powered element; responsive to execution of the set of instructions, send, by the primary controller in the powered element, a reply message to the ACPDC controller, wherein the computer readable program to send the reply message to the ACPDC controller further includes the computer readable program that causes the rack-mounted data processing system to: inject, by the primary controller in the powered element, the reply message for the ACPDC controller onto the primary alternating current power signal; receive, by the ACPDC controller, the primary alternating current power signal with the reply message; extract, by the ACPDC controller, the reply message from the primary alternating current power signal; determine, by the ACPDC controller, whether the reply message is from the powered element; and responsive to the reply message originating from the powered element, send, by the ACPDC controller, the reply message to a programming device external to the rack-mounted data processing system; monitoring, by the redundant controller in the powered element, the functions performed by the primary controller in the powered element to determine whether the primary controller is working improperly; and responsive to the redundant communication data being for the powered element and the primary controller working improperly, executing, by the redundant controller in the powered element, a set of instructions included in the redundant communication data in the powered element.