it is my first time which I want to use ethernet card to read some date from PLC my application/software . does any body has an expereince? is it possible introduce a example or any reference for this isuue? thanks a lot in advance.

Have you ever used WCF or Sockets?

If you are just trying to make one program send and receive data from another program, you should search for the phrase WCF example or Socket example.

What protocols does your PLC support/implement(a very common one is modbus over TCP)? Or are you responsible for writing this as well? Are you comfortable with working directly with sockets, or perhaps your PLC has an API that wraps all the socket stuff for you? More information is required to help you.

What you are asking is basically what I do every day for work so I am more than happy to help!