Hi Eswariah,
Siemens has Sinumerik HMI Programming Package which is an OPC Server. Please refer the product info on OPC foundation below:
http://www.opcfoundation.org/Products/ProductDetails.aspx?CM=1&RI=413&CU=1
You can pull up the data using SAP Pco which is an OPC client.
I hope this helps.
Regards,
Baiju.