Online automatic testing circuit and method of multichannel collection interface

Abstract

The invention belongs to the technical field of aviation electronics and specifically provides an online automatic testing circuit and method of a multichannel collection interface applied to a flight data collection system. According to the invention, a testing circuit is added to a differential output terminal of a multichannel analog switch of a multichannel analog signal collection circuit. The method sets different states of the single-pole triple-throw analog switch of the testing circuit by means of a collection control module, calculates signal voltage values of tested channels collected in different states, compares calculation results and theoretical values and check the deviation therebetween, and then determines whether an interface circuit fails. The method can detect such failure modes of the interface circuit as open circuit, short circuit and parameter drift of resistors. The testing circuit and the method can improve the self-testing capability of an interface resistor network. Especially for multichannel signal collection systems using multipath switches, the method can achieve interface testing while reducing testing hardware substantially.

Description

technical field [0001] The invention belongs to the technical field of avionics, in particular to a multi-channel acquisition interface online self-inspection circuit and method applied to a flight data acquisition system. Background technique [0002] The flight data acquisition system needs to collect a large amount of on-board sensor data, including dozens of analog voltage signals. In order to prevent the failure of the acquisition system from affecting the on-board signal, according to the requirements of ARINC717, an isolation resistance of not less than 150kΩ must be connected in series to the acquisition interface circuit of the analog voltage signal. [0003] Due to the large number of analog signal acquisition channels, there are also a large number of isolation resistors. If these resistors are abnormal during use and cannot be detected, the testability of the product will be greatly reduced. At the same time, the abnormality of the isolation resistance will also...

AI Technical Summary

Problems solved by technology

It is not advisable to add the test signal directly from the signal input terminal because it will affect the signal on the machine.

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