Hello Mohini,

If I understood correctly then, your requirement is to Read S7 300 PLC data in your VB based SCADA(Database)

You have different possibilities

1) OPC connectivity 

Plz go thru below link,

https://support.industry.siemens.com/cs/ww/en/view/21447513

The below link will provide you, sample application and documentation for designing of OPC client interface with C#. It's C# Based solution. If you are good in script then similar way you can design VB based OPC client.

_{Data acquisition and storage with an OPC client in C# and the SIMATIC NET .NET OPC Client API}

2) Using Industrial Data Bridge as part of SIMATIC WinCC but can be installed stand alone.

S7 300 will be provider and your own SQL data base will be as consumer. With the help of IDB you can exchange data between S7 300 to data base via TCON/TSEND blocks in S7300.

see the below link.

https://support.industry.siemens.com/cs/us/en/view/109483465 

3) I found one application note , attaching the same. This solution is based on TCP IP communication . Only you need to design VB code for getting data from PLC.

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New question published by syd_b is split to a separate thread with the subject OPC Software for a PC Ethernet connection and a CP343-1 Lean.

Best regards
Min_Moderator