The Control And Analysis Software Development For A On-line Mass Spectrometer

A gas analysis and control software for a on line quadrupole mass spectrometer was developed with VC6.0 in this thesis. This software is user friendly and provides convenient operation. The design of computer software and PLC software were described. The circuit and construction of the quadupole mass spectrometer were improved as well, so the function of automatic control of the mass spectrometer was enhanced extremely. On-line monitoring of 13 components in air and real-time data process were achieved with the self-made system, the measure error for micro-compounds and normal-compounds is 20%F.S and 5%F.S. respectively.(1) Software development for computerThe control and analysis software for computer was developed with VC6.0, using module design with different subprogram. The construction of the software is very clear and convenient to maintain. The software is made up of five parts: display module, communication module, gas manifold control module, data analysis module and storage module. The main functions of the software are list as following: the main display interface and the sub-interface development, the data base management development, communication with the hardware and achievement of the monitoring function of the instrument, storage of the analysis data, Offer interface to third program for data share.The software is user friendly and provides convenient operation. The user can manipulate it proficiently after simple study. The reliability of the software was increased by several measures including digital filter and Gaus algorithm. The method of summation fault tolerant technique, over time fault tolerant technique and conflict fault tolerant technique were added to assure smooth communication.(2) PLC software developmentPLC was used to monitor and control the state of environment temperature, vacuum, gas flow and magnetic valve. The software sends check commands to PLC every 1s to get the information of the instrument. The computer communicates with PLC using serial ports to control the magnetic valve for gas automatic collection system. The whole system features fast operation and high reliability.