A current acquisition diagnosis circuit and its failure diagnosis method

Abstract

The present invention proposes a current acquisition diagnostic circuit, including a current signal input terminal CH1, a sampling unit, a signal amplification unit and an analog signal digital signal converter ADC, wherein the signal amplification unit includes several parallel signal conditioning operational amplifiers, The signal amplification unit is also connected with a current source in parallel, the current signal input terminal CH1 is connected with a detection unit, and the detection unit is connected with an analog signal digital signal converter ADC. A failure diagnosis method for this circuit is also proposed, including failure diagnosis of switch SW1, switch SW18 and switch SW3; failure diagnosis of analog signal data signal converter ADC, signal conditioning op amp OP1 and signal conditioning op amp OP2; power supply I1 and switch SW17 carry out failure diagnosis; carry out failure diagnosis on sampling resistor R1 and sampling resistor R9. The invention has high self-diagnosis function, can detect failure of all devices in the current acquisition circuit, and has high diagnosis coverage.

Description

technical field [0001] The invention relates to the technical field of current acquisition, in particular to a current acquisition diagnosis circuit and a failure diagnosis method thereof. Background technique [0002] The current signal acquisition system on the industrial site is the most important input component in industrial control systems such as DCS and SIS. The current signal acquisition circuit will involve device failure, especially in failure protection devices, such as in automation technology, reliable devices Failure detection plays an important role. On the one hand, the safety of the process must be ensured, and on the other hand, the physical and life safety of, for example, the personnel operating the process must be ensured. [0003] However, current current signal acquisition systems have low diagnostic coverage, low safety, and poor usability for current signal acquisition circuits. The voltage of the voltage reference is used to detect the accuracy o...

AI Technical Summary

Problems solved by technology

[0004] The invention solves the problems of low diagnostic coverage, low safety, and poor usability of the current signal acquisition circuit in the prior art, and proposes a current acquisition diagnostic circuit and its failure diagnosis method, which diagnoses each of the ADCs through voltage scanning. A sampling code value, through the dynamic description of the reference current to diagnose the drift of the resistance itself does not exceed the accuracy

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