GE plc 串口通讯，VB编制，读取内存单元
.....................................\通讯程序（只读）
.....................................\................\frmMainShow.frm
.....................................\................\frmMainShow.frx
.....................................\................\MSSCCPRJ.SCC
.....................................\................\PLC.vbp
.....................................\................\PLC.vbw