Introduction - If you have any usage issues, please Google them yourself
Siemens PLC and VB communication process through free agreement (which is a class module, you can directly use)
Packet : 21840301siemens200plc-vb.rar filelist
西门子PLC和VB通讯程序
西门子PLC和VB通讯程序\ClsPlcS7.cls