Stage control system based on RS485 and Ethernet

 

 

LI Chun, GAO ChangShui

 

(College of Mechanical and Electionic Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China)

 

 

Abstract: Aiming at realizing the monitoring of the stage position in real time and lifting with high accuracy, the communication between hostcomputer and PLC, the FINS protocol and the communication instructions of variablefrequency drive were introduced, and the stage control system based on RS485serial communication and Ethernet was designed and implemented. Based on VC++6.0software development platform and the Winsock ActiveX, the position of the stage can be obtained by reading the PLC′s acquisition data of encoder pulse. The stage could be controlled to move independently or jointly by sending commands to the variablefrequency drive machines with the serial communication module. And a method of lifting control through writing the memory of PLC was presented. During the commissioning, a method of amending the stopping distance was presented to ensure the accuracy of stop position. The application results indicate that the system is stable, flexible and low cost, and can meet the design requirements.

 

Key words: stage; VC++; PLC;  FINS; variablefrequency drive; Ethernet; RS485