On-line Laser Marking System Applied In The Automatic Production Line

With nearly30years development, the working way of laser marking systems istransferring from manual operation to cooperation with complex Automatic Production Line.This thesis focuses on a line producing electrical parts controlled by PLC(ProgrammableLogic Controller)，which needs to design a on-line laser marking system. Including manyparts such as laser processing, vision recognition, barcode reading, data management,manufacturing statistics, the on-line laser marking system can assist to realize a series ofproduction process. The main contents can be summarized as follows:(1) Considering the production requirement and the possibility of cooperation betweenPLC Automatic Line and laser processing, a new method is proposed using PLC data registerand user-defined protocol as medium between PLC and laser marking system.(2) According to the system demands of data management, a database is designed onSQL Server platform. Using remote login on data-server by ODBC (Open DatabaseConnectivity), the on-line laser marking system realize managing manufacture data, such asadd, modify.(3) Using serial port and multithread programming technique, communication betweenon-line laser marking system and PLC, vision devices is realized. In system, there are twoimportant parts manipulating serial ports: querying serial port state in thread function anddeal with information in message handler function. In system, it is realized that multi-serialport do parallel working.(4) By handling information from vision devices, system can make statistics ofproduction, which means that on-line laser marking system has a function of storagemanagement(5) Based on MFC, the easily used software is developed, stability and reliability of thesoftware is validated by test.