Multi-channel Data Acquisition and Control System Based on LabVIEW

摘要

The system is a data acquisition and control system used for multi-channel. It is based on the integration of LabVIEW, PCI data acquisition card and intelligent self-tuning PID. Aiming at the ART's data acquisition card, the paper introduces on the allocation of LabVIEW and Non-NI data acquisition card. The modular design is adopted to realize real-time acquisition, processing, display, save and error messages for multi-channel signals. Utilizing exported standard signals and real-time signals via data acquisition card, we have controlled furnace temperature by intelligent self-tuning PID and made its range in certain variation change according to standard time temperature curve. And the practical application shows that the system works in the stable condition. LabVIEW, as a graphical language of program, is regarded as a standard of data acquisition and software of instrument control. With really powerful function, flexible multi-platform instruments and analysis software system, it can solve complex question in a short time [1]. The paper is based on the monitoring system design of refractory test furnace. By using dynamic link library, read AD data from Non-NI data acquisition card come true. After data conversation and processing then display on the computer, through DA channel of the data acquisition control card output signal to the intelligent self-tuning PID to control the test furnace. In the experiment, monitor several signals of temperature and pressure. According to the refractory test method (GB/T 9978.1-2008), the temperature of the test furnace should controlled to in accordance with curve T=345lg (t+1) +20. And test the sample's temperature to judge its heat-insulation properties, test the internal temperature and internal pressure of the furnace and the environment temperature to judge the effectiveness of the experiment. The system structure is shown in Figure 1.