creating item in OPC

I am wrting client application for OPC server which works in PROFIBUS with different Siemens CPU which includes S5 & S7.
If anybody can show me a peace of code how to create an item specifically for S7-300. Other thing I want to know is that when a memory block is already been defined, how to access existing memory variable from the CPU via OPC. Please help me. I am new in PLC and OPC communication. Sherebiah
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Go to the Kepware website: http://www.kepware.com/Spec_Sheets/Siemens_S5.html http://www.kepware.com/Spec_Sheets/Siemens_S5_3964R.html http://www.kepware.com/Spec_Sheets/Siemens_S7_MPI.html http://www.kepware.com/Spec_Sheets/Siemens_S7_200300400_TCPIPEthernet.html On the VB Tab, you can download examples at the bottom of the sheet. The information here may help you.
Mark

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