A multi-channel acquisition interface online self-test circuit and method

Abstract

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. The invention adds a test circuit to the differential output end of the multi-channel analog switch of the multi-channel analog signal acquisition circuit. Set the different states of the single-pole three-throw analog switch of the test circuit through the acquisition control module, calculate the signal voltage value of the detected channel collected in different states, and compare the deviation between the calculation result and the theoretical value to determine whether the interface circuit is faulty. Interface circuit failure modes, such as resistance open circuit, short circuit and parameter drift, etc., can be detected by the method of the invention. The invention can effectively improve the self-detection ability of the interface resistance network, especially for a system adopting multi-channel switches to collect multi-channel signals, it can greatly reduce the testing hardware while realizing the interface testing.

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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