4-20mA current redundancy output conversion circuit

Abstract

A 4-20mA current redundancy output conversion circuit is characterized in that the circuit comprises a first driving unit, a second driving unit, a driven load and a redundancy connection unit; wherein the first driving unit and the second driving unit are respectively a 4-20mA current output module; the first driving unit and the second driving unit are respectively connected with one end of the driven load through a redundancy connection unit; and the redundant connection unit is connected with the AO ports of the first driving unit and the second driving unit. According to the invention, the current redundancy output conversion circuit can be controlled, and when the current value in one 4-20mA current output module is too large, the redundancy output is discharged through the load and the adjacent 4-20mA current output module.

Description

technical field [0001] The invention relates to the field of integrated circuits, in particular to a 4-20mA current redundant output conversion circuit. Background technique [0002] Distributed Control System (DCS, Distribution Control System) is a multi-level computer system connected by communication network composed of process control level and process monitoring level, which integrates computer (Computer), communication (Communication), display (CRT) And control (Control) and other technologies (that is, 4C technology), realize the functions of decentralized control, centralized operation, hierarchical management, flexible configuration and convenient configuration of the system. Generally speaking, DCS is widely used in data acquisition, direct digital control, human-computer interaction, and monitoring and management. [0003] At present, with the rapid development of modern computer technology and communication network technology, DCS is developing in the direction ...

AI Technical Summary

Problems solved by technology

The problem with this solution is that simple automatic switching cannot be achieved, and the host computer must be used to realize the complex communication process and command judgment and reception, the timeliness is not high, and the switching method between the master and slave devices is not flexible enough

[0007] Although this method no longer uses the master-slave device switching method to achieve redundancy, and also avoids the complicated communication process of the host computer, but there are many components in the additional circuit of this method

For example, in the feedback circuit, not only the optocoupler isolation circuit but also the reference voltage source, comparator, amplifier and other components need to be used, which leads to complex circuit structure, which is easy to affect the original circuit, and the current output accuracy cannot be guaranteed.

In addition, this additional circuit needs to occupy the input and output ports of multiple 4-20mA current output modules, and there is a time delay in the judgment of the output current, which limits the application range of this method and limits the adopted 4 ~20mA Current Redundancy Module Output Port Mode

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