Measuring and Controlling of Analog signal Based on High-speed I/O port of PLC
Frequency signal is gotten from voltage signal by external V/F converter, and then is sent to highspeed counter of PLC. As a host, CPU222 of Siemens S7-200 series PLC is used. Through programming PLC, input voltage is measured by high-speed I/O channels. High-speed digital pulse of variable duty cycle produced by PLCs PWM pulse generator is turned into voltage signal of amplitude-adjustable after external RC low-pass filter circuit filter to achieve controlling of output analog. The method reduces the cost of measurement and control system via replacing expensive analog I/O modules. Peripheral circuit design and PLC program are given. Through analyzing and comparing data, it is found that the system can achieve±0.1％ accuracy.
PLC high-speed I/O A/D
Hongtao Ma Xiaojun Wang FenPing Zhou
College of Information Science & Engineering Hebei University of Science & Technology Shijiazhuang, China
国际会议
张家界
英文
393-395
2009-04-11（万方平台首次上网日期，不代表论文的发表时间）