Signal conversion device with disconnection detection function

Abstract

The embodiment of the invention provides a signal conversion device with a disconnection detection function. The signal conversion device comprises an external switch; a jumper resistor connected in parallel with the external switch; a first signal output line connected in series with a circuit formed by connecting the external switch and the jumper resistor in parallel; a second signal output line connected with the first signal output line in parallel and comprises a charging resistor; a charging capacitor connected in series with the charging resistor; and an isolated digital input receiver connected in parallel with the charging capacitor, connected in series with the charging resistor through a pin, connected in series with the first resistor through an input pin, connected in parallel with a line accessed from the pin, and connected in series with the charging point resistor. One end of the photo-transistor is electrically connected with a grounding pin of the isolation type digital input receiver, the other end of the photo-transistor is connected with the direct current power supply, and pulse voltage is input into the photo-transistor; and a detection result of the to-be-detected line connected through the external switch is determined based on voltage conditions output by the output end of the first signal output line and the output end of the second signal output line.

Description

technical field [0001] The invention relates to the technical field of signal detection, in particular to a signal conversion device with a disconnection detection function. Background technique [0002] With the application and development of automation technology in recent years, the applicable environment of programmable logic controller (PLC) is more and more extensive. The remote control and security system of the main engine of the ship, as the core automation system controlled by the main engine, has high requirements on the reliability of the control. Therefore, the input and output modules of the security control system may need to be equipped with a disconnection detection function to avoid faults in the sensor line. In some cases, the system loses monitoring of sensor failure data, which becomes a loophole that triggers security protection, resulting in dysfunction and protection failure. [0003] The disconnection detection function of the current ship host remo...

AI Technical Summary

Problems solved by technology

[0004] At present, the hardware used in the remote control security system of the marine main engine is basically monopolized by the self-owned hardware of the mainstream foreign remote control supporting manufacturers. The space for expansion and optimization is small, and the cost is generally relatively expensive.

Some other controllers directly use the 0-20mA analog current input module as the disconnection detection module, but because each type of external input needs to calculate the specific on-off resistance separately, so that both the disconnection current and the signal current can run In the range of 0-20mA, resulting in low system design efficiency, high material cost and not universal application

Since the disconnection detection function is of great significance to ship security control, most mainstream logic control hardware products cannot directly meet the function of synchronous detection of signal and disconnection, and cannot be applied to this field to realize logic control

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