A do module of a triple redundant system and its output voting circuit

Abstract

The embodiment of the present invention discloses a DO module of a triple redundant safety system and its output voting circuit, including a first drive circuit, a second drive circuit and a third drive circuit, a fourth drive circuit, a first controllable switch, the second controllable switch, the third controllable switch and the fourth controllable switch, the input ends of each driving circuit are connected to the first microprocessor, the second microprocessor, the third microprocessor, and the main control unit of channel A unit, B-channel master unit, and C-channel master unit outputs. Each drive circuit controls a controllable switch, and four controllable switches form a circuit structure of two strings and two parallels. The first group of input signals corresponding to the A channel, the second group of input signals corresponding to the B channel, and the first When at least one of the three sets of input signals is normal, at least one of the two-series-two-parallel circuit structures is turned on, so that the degraded operation mode of 3-2-1-0 can be realized, and the safety performance of the system can be 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

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