Strengths of the edge on the OPC UA

The strengths of the edge on the OPC UA scenario include the following:

• The OPC interface abstracts the underlying device that acts as a data source. This means there is no need to implement and maintain a connector for each fieldbus protocol that the edge connects to.
• The OPC UA server is typically linked to more than one PLC or DCS that have the same underlying industrial protocols. A single OPC server can collect the data coming from more than one PLC, therefore simplifying the deployment of the edge. Moreover, the OPC UA server can act, through its discover service function, as an OPC UA server concentrator. This means that it can also expose the data coming from OPC UA servers that are linked to different underlying industrial protocols.
• Since the edge is not connected directly to the control network, it is easier to deploy it in a DMZ, as stipulated by the ICS standards.
• There is no COM or DCOM communication between the edge and the OPC UA server. This means that there is no need to deal with the DCOM communication mechanism based on TCP dynamic ports.
• Since the edge must implement just the OPC UA client interface, it is not restricted to running just on a Windows box.