Abstract: A system receives AC power from an Uninterruptable Power Supply (UPS) on an AC power cable. The AC power cable couples a primary AC line voltage or a switched secondary AC line voltage depending on the quality of the primary AC line voltage. The UPS has a modulating circuit with a power line carrier protocol that receives a power down signal from the UPS if the primary AC line voltage indicates that the system should power down in a controlled manner or take other power down actions. The modulating circuit generates a modulated power down signal that is coupled to the AC power cable. The system has a corresponding demodulating receiving circuit with the power line carrier protocol that receives the modulated power down signal and regenerates the power down signal. The power down signal is coupled to circuitry in the system that initiates power down sequencing options.

Abstract: A system receives AC power from an Uninterruptable Power Supply (UPS) on an AC power cable. The AC power cable couples a primary AC line voltage or a switched secondary AC line voltage depending on the quality of the primary AC line voltage. The UPS has a modulating circuit with a power line carrier protocol that receives a power down signal from the UPS if the primary AC line voltage indicates that the system should power down in a controlled manner or take other power down actions. The modulating circuit generates a modulated power down signal that is coupled to the AC power cable. The system has a corresponding demodulating receiving circuit with the power line carrier protocol that receives the modulated power down signal and regenerates the power down signal. The power down signal is coupled to circuitry in the system that initiates power down sequencing options.