Design And Implementation Of The Electrochemical Workstation Acquisition Module

As a hot area of scientific research, electrochemical analysis is paid great attention to by many countries. With the continued development of electrochemical analysis theories, electrochemical workstation based on various electrochemical analysis methods, has become one of the necessary equipments in many laboratories and industrial control fields. At the same time, with both the digital electronic technology and digital signal processing technology mature, the traditional analog electrochemical workstation is gradually replaced by digital electrochemical workstation. Focusing on the characteristics of the electrochemical tested signal, this paper is aimed at studying the electrochemical workstation acquisition technology, designing the electrochemical workstation acquisition module, and verifying the mudule in the electrochemical test. The main works are as follows:1. According to the requirements of acquisition module, this paper studies the overall framework, designs a dual-channel, synchronous and high-speed signal acquisition board, and realizes the real-time sampling of the tested signals in the electrochemical analysis.2. To solve the synchronization errors of the two channels of acquisition module, this paper studies the channel time mismatch error calibration technology which is based on Farrow stucture, utilizes the Farrow filter to realize the compensation of fractional time delay between the two channels, and completes the design on FPGA platform achieving the goal with time mismatch error less than 1ns.3. In order to reduce the sampling rate of acquisition module, this paper studies the multistage signal processing technology which is based on the cascade stucture of polyphase decimation filter, makes use of the distributed algorithms and pipleline technology to design the polyphase decimation filter, and completes the logic on FPGA platform achieving the goal with 1-100000 variable signal decimation range.4. According to the characteristics of the electrochemical tested signal, this paper studies the data storage technology of the signal acquisition module, uses two ways with both the structure of a single FIFO buffer and the structure of two FIFOS ping-pong buffer to achieve the data storage and upload of different sample rates.Finally, this paper tests and verifies the function and performance of the acquisition module on the electrochemical workstation platform. According to the result of test and verification, both the function and performance meet the requirements of the system.