Developer OPC UA server in C#|OPC UA Implementation: Stacks, Tools, and Samples|Forum|OPC Foundation

Hello everyone ,

I am new comer and I need guidance from from you guys :

Just a background,  We have a Web based application developed in MVC C# and MSSQL Server   and we have incorporated various drivers like modbus , S7 Drivers for siemens , OPC Ua client , Mitsubishi in the application to communicate to various customer machines PLC

. Now for the customer needs the data  to be transmitted  through OPC  in their MES application for monitoring and auditing purposes . 

a) Can someone please guide us how  we can achieve this ? 

b) Do we  need to build an OPC UA server in our application  or Some kind of a OPC gateway?

c) If we build an OPC Server then how do we  convert the received values from the PLC address and map various machine tags ?

Forgive me if this question  has been asked before  or I may  sound to ignorant and too ill informed.

Vinay