Data Acquisition Module Design Of Distributed Fiber Temperature Sensing System

Distributed optical fiber temperature sensor technology is one of the hot spots in the sensor measurement field in recent years.In many specific environmental situations,it is required to monitor the temperature of a large number of locations at the same time.At this time,the conventional point temperature sensor requires a very large cost and time for continuous measurement over long distances,while the distributed fiber temperature sensing technology can Solve this problem well.A complete fiber-optic temperature sensing system,including its matching data acquisition module,the depth of data this module can capture determines the maximum distance the fiber can be measured in a temperature-sensing system,the data acquisition rate of the module,and the data processing method.The interfaces for data transmission with computers all affect the system's consumption of working hours.The main work of this dissertation is to design the data acquisition module which plays an important role in the distributed optical fiber temperature sensing system.The data acquisition module includes functions such as signal acquisition,data processing,data transmission and hardware driver,and is implemented through PCIe and LAN interfaces.High-speed communication with the computer.The main work is as follows:1.The hardware structure of the acquisition system is designed to complete the design and implementation of the data acquisition system hardware.The system hardware is implemented using the backplane and sub-board structure.The backplane mainly implements high-speed interface protocol transmission,digital signal processing,and analog signal channel processing;the sub-board mainly implements analog signal A/D conversion,data storage,and hardware internal data accumulation.2.FPGA-based implementation of the collected data processing.In a traditional fiber optic temperature sensing system,data collected by a single data acquisition board is usually processed by software,which reduces the real-time performance of the entire system.On this basis,the system has achieved a maximum accumulation of over 60,000 acquisition data hardware,which greatly facilitates subsequent data processing.3.Study and analyze the protocol specification of the interface protocol and implement the communication function of the data transmission interface within the FPGA based on Altera Corporation.PCIe interface accords with PCIe 2.0 standard,each serial data transmission rate reaches 380MB/s;The LAN interface is Gigabit Ethernet,the data transmission rate is 900Mb/s.4.Design high speed interface driver.The PCIe interface driver is implemented by calling WinDriver's API function.The LAN interface driver is implemented by calling the driver provided by Winpcap.The entire system realizes the high-speed acquisition and trigger control of analog signals,and can flexibly select the number of times of data accumulation,and provides PCIe and LAN high-speed interface transmission capabilities.After testing,the designed data acquisition module can meet the requirements of distributed optical fiber temperature sensing system for data acquisition depth,data processing methods,module working time and data acquisition accuracy.