The Realization of the Communication Between LabVIEW and PLC Based on Serial Port ActiveX Control-MsComn

Serial port communication between PC and Siemens PLC is realized by using the graphic programming language LabVIEW.By applying MsComn control of ActiveX,the data of the lower computer during its interruption can be read,thus improving the real-time and reliability of the system.Using the Siemens S7-200 potentiometer simulator,the monitoring system design of temperature and pressure is realized.