Questions

1. What is the main difference between OPC Classic and OPC UA?
   1. OPC Classic uses COM/DCOM, while OPC UA is platform-independent
   2. OPC Classic uses TCP, while OPC-UA uses HTTP
   3. OPC Classic does not have a data model, while OPC-UA does

2. What is the mechanism used by DCOM to send and receive information between COM components in a transparent way on the same network?
   1. Marshalling
   2. Remote Procedure Call
   3. Dynamic TCP ports

3. What is the main advantage of using OPC rather than the legacy industrial protocols of the device or equipment?
   1. OPC allows us to query for industrial data in the most efficient way
   2. OPC allows us to query for the industrial data by means of a Windows box
   3. OPC abstracts the connected device, providing standard and common interfaces to query its data

4. How can we secure the communication channel between an OPC UA client and an OPC UA server?
   1. If the security...