Design of ARM Based Fault Monitoring & Diagnosis System (Front-end Data Acquisition and Communication System)

Railway signal system is a complex control system, which is made from a variety of electrical and mechanical equipment. It plays an important role in safety, efficiency and speed of railway operation. In our country, most of the railway marshalling yards or stations are located away from the urban centers. Many of signal equipments usually connect with out-door information acquisition objects or control objects that are so frequently exposed in the lightning environment and cause the indoor signal equipments affected by lightning-induced overvoltage easily. Besides, transient signal changes due to operation changes can also cause overvoltage inside the signal equipments, which threate electronics equipments severely. Therefore in order to better identify and diagnose faults, and guarantee the railway efficiency and safety, it’s essential to monitor and acquire the transient signal.This thesis designs a kind of the ARM-based fault monitoring and diagnosis system associating with Thunder Recorder that can make multi-point monitoring to diagnose overvoltage induces by lightning after studying and analyzing transient overvoltage.The whole system consists of two major parts:the front-end data acquisition system based on single chip microcomputer and ARM9-based central control processing part. Using RS-485 bus, it can make a distributed monitoring acquisition network. Front-end data acquisition part uses DS80C320 microcontroller as the main controller, TLC5510 as the A/D conveter to achieve the trigger and acquisition. functions. Central control processing part uses Samsung S3C2440A ARM9 family of processors as the core control device and Linux as the operating system with data storage and display. So the whole system can finish the fault diagnosis function.This thesis gives an overall design of the fault monitoring and diagnosis system and the method of associating with the Thunder Recorder and designs the related circuit and software programs. For The ARM9 center processing part creates software development environment and transplants the Boodloader and Linux operating system successfully. Finally, the thesis summarizes the study and points out the inadequacy of the system and gives the suggestion to improvement.