The Laser Gas Analyzer Data Acquisition And Processing

In order to monitor emissions meeting the requirements in industrial production,and in order to avoid explosion and some other danger in industrial production or in the steel smelting process due to the gas chemical,reaching and developing a good stability,high sensitivity,miniaturization and portable gas analysis equipments are essential.Tunable diode laser absorption (TDLAS) has many advantages than other gas analysis techniques.Now the great demand for laser gas analyzers in the dometic, but few dometic manufacturers can produce such products.So reaching and developing laser gas analyzer is necessary.This dissertation is based on laser gas analyzer,and using Verilog HDL reaches to and completes data acquisition, storage and transmission in the FPGA chip.First, the reseach situation and development trend of the gas analysis are analyzed in the dissertation,then TDLAS principles and FPGA technologies are described in detail.Finally,data acquisition,data storage,data transfer,the implementation of these three areas is discussed in detail.The data acquisition part includes the timing control for ADC CS5361and the average of ADC CS5361converting the digital signal.In this dissertation the average processing is a simple average method,rather than directly using divide.FPGA needs the collected data to a microcontroller.Beacause the clock of collected data and transmiting data is different,so in this paper asynchronous FIFO is used to store data.In the dissertation, the I2C bus is used for tranfering data between the FPGA and microcontroller.By reading literatures and books, they generally implement the host program in the FPGA chip to read data stored in the EEPROM.This dissertation implementes the slave interface program in the FPGA chip.The design uses hardware description language Verilog HDL.I complete the entire process of design,synthesis,simulation,layout,etc,in Xilinx’s development tool,the ISE12.3.Simulation is the software that comes with the ISE,and simulation results meet the requirements.