DO (Digital out) module of triple modular redundancy system and output voting circuit thereof

Abstract

The embodiment of the invention discloses a DO (Digital out) module of a triple modular redundancy system and an output voting circuit thereof. The DO module comprises a first drive circuit, a seconddrive circuit, a third drive circuit, a fourth drive circuit, a first controllable switch, a second controllable switch, a third controllable switch and a fourth controllable switch, wherein input ends of the drive circuits are connected with output ends of first microprocessors, second microprocessors, third microprocessors, A-channel main control units, B-channel main control units and C-channelmain control units. Each drive circuit controls one controllable switch, the four controllable switches form a two-series two-parallel circuit structure, and at least one path of the two-series two-parallel circuit structure is switched on when at least one group of input signals in a first group of input signals corresponding to an A channel A, a second group of input signals corresponding to aB channel and a third group of input signals corresponding to a C channel is normal, so that a 3-2-1-0 degraded running mode can be realized, and the security performance of the system is improved.

Description

technical field [0001] The embodiment of the present invention relates to the technical field of safety systems, in particular to a DO module and its output voting circuit in a triple redundancy system. Background technique [0002] Triple Modular Redundancy system is referred to as TMR (Triple Modular Redundancy), which is the most commonly used fault-tolerant design technology. Three modules perform the same operation at the same time, and most of the same outputs are used as the correct output of the voting system. The DO (Digital out, digital output port) module in the triple redundancy system is designed to implement three redundant and fault-tolerant channels on one IO (Input / Output, input / output) board. In the prior art, the output voting circuit of the DO module is composed of a hexagonal drive circuit composed of six electronic switch tubes, and implements a 3-2-0 degraded operation mode. For details, please refer to figure 1 . [0003] figure 1 Among them, A, B ...

AI Technical Summary

Problems solved by technology

However, when two IO channels fail at the same time, the final output channel will enter a power-off safe state, which will lead to unplanned shutdown of the factory, thus bringing greater economic losses to users

Images