Bilateral input/output port circuit

Abstract

The invention discloses a bilateral input / output port circuit. An OC output driver U0 and couplers U1 and U2 realize the completion of the input and the output of '28V ground / suspend' discrete magnitude signals through isolation resistors including R1, R2 and R3; OC output inverters N1 and N2 and couplers U3 and U4 realize the input and the output of '28V / suspend' discrete magnitude signals through isolation resistors including R4, R5 and R6; and OC output inverters N3 and N4 and couplers U5 and U6 realize the input and the output of '28V / ground' discrete magnitude signals through isolation resistors including R7, R8 and R9. The bilateral input / output port circuit provided by the invention has the advantages as follows: the structure is simple, compact and reasonable; the input / output speed is fast; the electric isolation requirements can be met; self-detection of the circuit can be finished; and the circuit can be used as an input port or an output port.

Description

technical field [0001] The invention relates to an input / output interface (Input / Output Port, I / O port) circuit, especially with photoelectric isolation function and self-check function. Background technique [0002] In modern avionics systems, 28V discrete signals generally have three forms: "28V ground / suspended, 28V / suspended, and 28V / ground". In order to complete the test of the discrete signal of the avionics system, it is necessary to provide the corresponding type of test channel for the avionics system under test, that is, the input / output interface circuit. In the design process of complex avionics test systems, due to various reasons such as many test channels and complex signal types, it often occurs that the input / output direction of the 28V discrete test channel is reversed, so that the avionics test system can be debugged During the process, it is necessary to change the input / output direction of the corresponding discrete channel, the system lacks flexibility...

AI Technical Summary

Problems solved by technology

[0003] In order to overcome the shortcoming that the input / output direction of the prior art cannot be flexibly changed, the present invention provides a bidirectional input / output interface circuit, which can complete the change of the input / output direction of the 28V discrete signal through the setting of the control bit, and at the same time through this method The designed circuit has electrical isolation function and self-test function

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