Abstract: A fan power supply system having a pair of voltage supplies, one producing a higher voltage than the other. A switch selects one of the voltage supplies in response to a control signal. A DC/DC converter is connected to the selected one of the voltage supplies for producing a current greater than current fed to the DC/DC converter by the selected one of the voltage supplies. A fan is fed by the current produced by the DC/DC converter. The fan produces a train of pulses representative of the rotational speed of the fan. A microcontroller encodes the train of pulses produced by the fan as a function of whether the selected one of the pair of voltages has the higher voltage or the lower voltage. A decoder produces the control signal in accordance with the encoding by the microcontroller.

Abstract: In a highly available storage system, an enclosure includes first and second power supplies, and first and second controller boards. Each of the first and second controller boards includes first and second serial bus controllers. First and second serial buses are coupled to both of the first and second serial bus controllers on each of the first and second controller boards. The first serial bus is coupled to the first power supply, while the second serial bus coupled to the second power supply. The first and second serial buses are used for exchanging enclosure management and environmental information between the first and second power supplies and the first and second controller boards. The first and second serial buses are coupled to isolation switches so that redundant modules can operate if a serial bus controller fails.

Abstract: In a highly available storage system, an enclosure includes first and second power supplies, and first and second controller boards. Each of the first and second controller boards includes first and second serial bus controllers. First and second serial buses are coupled to both of the first and second serial bus controllers on each of the first and second controller boards. The first serial bus is coupled to the first power supply, while the second serial bus coupled to the second power supply. The first and second serial buses are used for exchanging enclosure management and environmental information between the first and second power supplies and the first and second controller boards. The first and second serial buses are coupled to isolation switches so that redundant modules can operate if a serial bus controller fails.

Abstract: A system and method for determining a fault threshold for an operational module according to the model of the operational module are described. The system includes an operational module, a storage unit, and a monitoring unit. The operational module has circuitry for producing a characterization signal with an electrical characteristic that uniquely correlates to the model of the operational module. A storage unit maintains an association between at least one parameter value and a fault threshold. A monitoring unit is in communication with the operational module to receive the characterization signal and with the storage unit. The monitoring unit measures the electrical characteristic of the characterization signal to derive a parameter value therefrom and accesses the storage unit to determine the fault threshold associated with the derived parameter value.