Data Acquisition And Processing Embedded System Of OTDR Based On ARM-Linux

Optic Time Domain Reflectometry (OTDR) is the instrument as a token the time domain of transmission characteristic of fiber. OTDR can measure the optical power attenuation of optical fiber links,displays for detecting and positioning and measuring the event of optical fiber links in any position.OTDR has become the important instrument of the optical fiber fault detection. Along with the increase of OTDR performance requirements,the OTDR control system also put forward higher requirement.Using powerful embedded processors and embedded operating system appears more and more necessary.The paper analyzed the principle,design and the key technology of high resolution. Design scheme based on the ARM-Linux OTDR high-speed data acquisition and processing system was proposed.The paper completed system hardware and software design based on the ARM+FPGA structure and the core of Linux.In the hardware design,in order to realization the weak signal detection,the high-gain and high-bandwidth preamplifier circuits was designed,which using the analog company'chip AD4817.Using the analog company'chip AD9627 realize high speed data acquisition. Using the double port Cy7c028 RAM realize high speed exchange between FPGA and ARM.In the software design,in order to better and more effective management system function,Linux system was transplanted.In ARM-Linux architecture,based on the s3c2440 platform,LCD driver,USB device drivers and data processing applications was designed.By modifying the kernel of ARMLinux,we made ARM capable of getting the high speed data from its external device FPGA by the FIQ.Then a user process can get the data from the system space and computing processing data.The paper realized weak signal detection and high-speed data acquisition.The paper based on the structure of FPGA and ARM9. The FPGA realizing a high-speed data acquisition,ARM9 embedded operating system of Linux,realized the data processing and function expansion. Through the measurement of optical fiber links, actually realized the system function,meet the design requirements.