Multi-protocol data transducer used for vehicle fault diagnosis and its diagnosis processing method

Abstract

The invention discloses a multi-protocol data converter for vehicle fault diagnosis, which comprises a vehicle connection interface and a RS232 interface connected with a microcontroller; a converter feed circuit and an a K line signal condition circuit, a CAN signal condition circuit and an ALDL signal condition circuit are respectively arranged between the microcontroller and the vehicle connection interface; a RS 232 signal condition signal is arranged between the microcontroller and the RS232 interface; the vehicle connection interface adopts a standard EOBD and an OBD II connector which meet ISO 15031-3 and SAE J1962 prescriptions; the microcontroller is embedded with a vehicle protocol automatic search module and a protocol diagnosis module. The protocol diagnosis module comprises a diagnosis processing submodule of ISO15765 / SAE J1939 protocol and a diagnosis processing submodule of SAE J1850 / ISO 9141 / ISO 14230 / KW1281 / ALDL protocol; an SAE J1850 signal alignment circuit is arranged between the microcontroller and the vehicle connection interface and used for realizing signal condition by two ways of J1850 VPW andJ1850 PWM; the microcontroller and each signal condition circuit are connected by the interface circuit of the microcontroller; at the same time, the invention also discloses a diagnosis method for the data converter.

Description

technical field [0001] The patent of the present invention relates to a data converter for automobile fault diagnosis, in particular to a multi-protocol data converter for automobile fault diagnosis in the development of PC-based vehicle fault diagnosis system and handheld vehicle fault diagnosis equipment. Background technique [0002] Since the 1950s, through the combination of automotive technology and electronic technology, the application of electronic technology in automobiles has become wider and wider, and it has provided automotive electronic control systems with fast speed, powerful functions, reliable performance, and low cost. It greatly improves the power, economy, safety and comfort of the car. However, due to the unprecedented complexity of the vehicle system due to the electronic control of the vehicle, it has brought more and more difficulties to the vehicle maintenance work. In response to this situation, by the end of the 1970s and the beginning of the 19...

AI Technical Summary

Problems solved by technology

The USB diagnostic protocol conversion box in the above technical solution can only be connected to the CAN bus or the K bus, and cannot better adapt to the diversity of vehicle diagnostic communication forms; when the communication data exchange between the vehicle and the diagnostic equipment, its USB diagnostic The protocol conversion box can only realize the conversion between CAN bus or K bus data flow and USB bus data flow, therefore, the corresponding diagnostic equipment must have the protocol processing function of the network layer and data link layer of CAN bus or K bus, so that Increased complexity of diagnostic equipment

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