Self-diagnosis detection circuit, device and method of digital output channel

Abstract

The invention provides a self-diagnosis detection circuit, device and method of a digital output channel, belongs to the technical field of industrial control, and aims at solving the problem that a technical scheme of simple and reliable self-diagnosis of the digital output channel lacks in the prior art. The circuit comprises an electromagnetic relay, and the electromagnetic relay is set to receive a digital control signal and output an electric signal converted by an electromagnet to an external circuit; the electromagnetic relay comprises two groups of output contacts, one group of contacts serves as dry contacts to form a dry contact output branch, and the other group of contacts is connected to an input signal control circuit to form a detection read-back branch. Thus, the simple and reliable pure-hardware detection circuit and method can be used, design of the self-diagnosis circuit of the digital output channel is simplified, and the circuit, device and method are suitable for self-diagnosis of wet-contact and dry-contact type digital output channels simultaneously.

Description

Technical field [0001] The present invention relates to the technical field of industrial control, in particular to the technical field of a distributed control system for the industrial control industry, and more specifically, to a digital output channel self-diagnostic detection circuit, detection device and detection method. Background technique [0002] In the field of industrial control, especially nuclear power DCS (English full name Distributed Control System, Chinese translation for distributed control system), which requires high system security, the system availability rate is generally required to reach 99.99%. The diagnostic coverage is an important measure to improve the availability, so it is very important for those skilled in the art to study the self-diagnostic design of the output channel in the DCS. [0003] For example, the Chinese patent application No. CN201610730083.9 discloses an FPGA-based digital output channel self-check system. The self-check system incl...

AI Technical Summary

Problems solved by technology

figure 1 The following technical problems exist in the detection circuit of the wet contact output (providing voltage to the outside) in the corresponding digital channel: In order to achieve the isolation between the channel power supply (48V+) and the digital circuit ground (3V3GND), an optocoupler or other isolation circuit is required, so increases the complexity of the circuit

figure 2 The following technical problems exist in the detection circuit of dry contact output in the corresponding digital channel (no voltage is provided externally, only contacts are provided): since the query power supply is connected to the outside of the board, the detection circuit cannot form a loop, and the circuit of the query power supply cannot be used Perform channel self-diagnosis

[0005] Therefore, the technical solutions in the prior art exist: they can only be used for the monitoring of the wet contact output type, but cannot be used for the readback detection of the dry contact output channel, and a special isolation circuit is also required

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