Maintainable distributed fail-safe real-time computer system

Abstract

A distributed maintainable real-time computer system is provided, wherein the real-time computer system includes at least two central computers and one, two or a plurality of peripheral computers. The central computers have access to a sparse global time, have identical hardware and identical software, but different startup data, wherein each functional central computer periodically sends time-triggered multi-cast life-sign messages to the other central computers according to a time plan a priori defined in its startup data, and wherein the peripheral computers () can exchange messages () with the central computers (), and wherein at all times one central computer is in the active state and the other central computers are in the non-active state, and wherein after the apparent absence of a life-sign message of the active central computer expected at a planned reception time, that non-active functioning central computer which has the shortest start-up timeout takes over the function of the active central computer, and wherein each central computer () consists of three independent subsystems, an application computer (), a storage medium having the startup data () characteristic of the central computer () and an internal monitor (), wherein the internal monitor () periodically checks the correct functioning of the application computer (), and wherein upon detection of an error the monitor () initiates a hardware reset and a restart of the application computer (), and wherein preferably the active central computer initiates a maintenance action after an apparent absence of the life-sign messages expected at the planned reception times from a non-active central computer, which action can lead to the repair or replacement of a permanently failed central computer.