| 摘要 |
<p>Circuit modules for providing digital or analog outputs from computational devices in a manner tolerant of malfunctions in module components. In the digital output embodiment, two independent voting circuits (18a, 18b) provide outputs to series connected switches (20a, 20b) to provide a fail-safe condition for most malfunctions of the switches or the voting circuits. Two modules (22, 24) in parallel increase reliability and permit replacement of a defective module without affecting output through the other module. In an analog output module (60a), two independent voting circuits (62a, 64a) provide outputs to separate digital-to-analog converters (66a, 68a) whose outputs are compared to generate a validity signal used to activate an output switch (74a). The validity signal can be combined logically with the switch (74b) status of another module (60b), to determine which module should be activated. An inactive module can be replaced without affecting the analog output.</p> |
