摘要 |
A system is used with a plurality of modules, each module requiring galvanic isolation from the other modules. Galvanic isolators are employed, each having an input and an output, the output galvanically isolated from the input, the output responsive to the input according to a response characteristic of the isolator. Each module has, a respective first isolator and a respective second isolator. The input of each respective first isolator and each respective second isolator for each module is disposed controllably to receive an activation signal from the module indicative of a module fault to be annunciated or to receive a test signal from the module, the test signal being smaller than the activation signal. The outputs of the respective first isolators are aggregated to a first node and the outputs of the respective second isolators are aggregated to a second node. A selection circuit selects from the first node and the second node, yielding a fault signal output when the selected node satisfies a predetermined condition. An analog-to-digital converter is coupled with each of the nodes, the analog-to-digital converter disposed to sense an output from one of the isolators indicative of its response characteristic in the event of a test signal being applied to the isolator.
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