6.4.5.1 PC与西门子S7-200PLC串口通信\Form1.frm ....................................\MSSCCPRJ.SCC ....................................\PLC端程序\plc2.txt ....................................\.........\plc224.mwp ....................................\工程1.vbp ....................................\工程1.vbw ....................................\PLC端程序 6.4.5.1 PC与西门子S7-200PLC串口通信