Patent ID: 8053927

Claim:
An uninterruptible power supply for providing power to a load, the uninterruptible power supply comprising: an input to receive input power; an output to provide output power; a backup power device that provides backup power; a power circuit coupled to the input, coupled to the backup power device and coupled to the output to provide power derived from at least one of the input power and the backup power to the output, the power circuit having a first power interface module having a plurality of first power modules; a controller; a first sense line coupled to the controller and coupled to the first power interface module and the plurality of first power modules; and a return line coupled to the controller and coupled to the first power interface module and the plurality of first power modules; wherein the controller, the first power interface module and the plurality of first power modules are configured and arranged such that the controller identifies a revision level of the first power interface module and a revision level of the plurality of first power modules, based on a voltage level detected by the controller across the first sense line and the return line.