The Charles Stark Draper Laboratory, Inc.

T Basil Smith

John F McKenna, Jr

John R Howatt

A system having a plurality of redundant channels operating in tight synchronism wherein input information received in one or more of said channels is distributed to all the other channels. The received information in each channel is retransmitted to suitable voter circuitry in each channel so as to provide one or more voted outputs in each channel based on the distributed and retransmitted information from all the channels. The voted outputs from all unfailed channels are substantially identical and the voted output from a failed channel will not be identical to that of the unfailed channels.

Multi-channel redundant processing systems

A fault-tolerant clock system for providng digital timing signals (system clock signals) is provided by a plurality of clock sources. Each clock source receives as inputs the generated clock signals from all the other clock sources and contains receiver circuitry to derive a system clock signal from said clock sources which is the consensus clock signals of the other sources. Each clock source generates and distributes to the other clock sources a clock signal which is phase locked to the derived system clock from its clock receiver. In a system of (2r+2) clock sources (r+2) of them will remain phase locked to each other despite up to r clock source failures. Any clock receiver responsive to any (2r+1) of the clock sources can therefore derive a correct system clock despite up to r clock source failures.

Growing community of inventors

Sudbury, MA, United States of America

T Basil Smith