Study On Data Acquisition And Processing Technology Of OTDR Based On FPGA

OTDR is an important test instrument in the optical fiber communication system,it is the representation of transmission properties of fiber.The specific performance is that it can measure the power attenuation of whole fiber optical link and provide the attenuation details with the whole optical fiber length,such as the detection locate and detecting fiber optic link to any position on the event.In order to satisfy the measurement requirements of the distributed optical fiber sensor, OTDR should not only have great dynamic range, high resolution, etc, but also have the strong data exchange capacity and fast data processing ability with the computer.Based on thorough study of OTDR principle and design, based on current OTDR, design scheme based on FPGA OTDR signal acquisition and processing technique was proposed. Paper by using the FPGA as the main controlling unit of lower level computer to realize collection of data acquisition about Rayleigh scattering after amplification of A/D conversion of data,then to do the corresponding processing to collection data.Finally serial interface will be developed the data collected through serial port transfer to the PC and on the PC to use vc++programme to display the data collected.Paper realized the high speed data acquisition and point-to-point data transmission. Xilinx FPGA adopts the Spartans series XC3S400PQ208devices realize high speed data acquisition, using common RS232serial port as point-to-point data transmission chip. Through the measurement of actual fiber optic link, realized the system function, achieve the design requirement.