Design Of Data Acquisition And Transmission System For Industrial CT Based On Spartan-6 FPGA

Industrial Computed Tomography (ICT) technology is an advanced nondestructive testing technology in industrial field. As one of the key part of the industrial CT, the reliability, stability and real-time of data acquisition and transmission system will directly affect the quality of reconstructed images. As development and application requirements of industry CT technology unceasing enhancement, the various performance indicators demand of industrial CT is higher and higher, especially the changes of modern industrial CT scanning mode and the development of detecting system demand the capacity and processing speed of data acquisition and transmission increase exponentially.This topic mainly research and design based on FPGA Xilinx high-speed reliable industrial CT data acquisition and transmitting system. The paper firstly discussed the function and performance of the industrial CT data acquisition and transmission system, so as to determine the overall design scheme of the system. Then, based on characteristic of industrial CT data acquisition and transmission system, separately from choices of hardware platform and software platform, high-speed data acquisition part design method based on FPGA ISE chip was presented , and the design of transmission part of hardware platform with software application based on the EDK was completed, and finally the system performance was tested.Based on Altera FPGA,the hardware design and the communication protocol compilation of the data interface between detection system and the system was completed, and the board level validation was also passed, which validated the correctness of communications protocol based on Manchester codes.The Altera QuartusⅡprogram was transplanted into the Xilinx ISE platform. Design of data acquisition and transmission system based on FPGA plus Xilinx MicroBlaze soft processor architecture was completed, and the test software of PC based on WinPcap using Microsoft VC++ 6.0 was designed,the experimental verification work of the data acquisition and transmission system was also finished.Spartan-6 XC6SLX45T chip from Xilinx company was adopted as the hardware platform. In the FPGA platform, the serial data from detection system after A/D conversion were transmitted to system for series-parallel conversion through FIFO after the cache.And then through double port RAM of MicroBlaze subsystem, the FPGA logic will mount to the PLBv46 bus of MicroBlaze system, exchanging data system structure between MicroBlaze and FPGA was also realized.This structure makes MicroBlaze processors can directly read data from double port RAM, which greatly improved the integrity of system.In order to efficiently use LwIP TCP/IP protocol stack to realize reliable data transmission, a RAW mode of LwIP and an accessible Standalone mode of OS were chose. A network application design was realized based on RAW API in MicroBlaze system. Also, data transmission to PC through the network for store was achieved.The transmission speed and reliability of the data interface between the detection system and data acquisition and transmission system and of whole system were tested in the experimental platform, and test results shows that this system has good performance, preliminary reached system design of expected results.In the paper, the design of industrial CT data acquisition and transmission system played a FPGA logic part with embedded MicroBlaze soft IP processor advantage, fully utilizes the parallelism of FPGA and processing ability of soft processor, improves the system integrity further than the FPGA plus ARM9.For the other dual-core data acquisition and transmission system design and development,it has a certain degree of reference value.