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 

1. 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

1. 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

1. How can we secure the communication channel between an OPC UA client and an OPC UA server?
   1. If the security mode is None, the channel will be set using all the security mechanisms available
   2. If the security mode is Sign, the OpenSecureChannel is sent using the PrivateKey of the client Application Instance Certificate as a signature

1. What is a session in OPC-UA client-server communication?
   1. A session is a logical connection between a client and a server
   2. A session is the underlying communication protocol between a client and a server
   3. A session is a mechanism for solving any issues that occur at the protocol level

1. What is the main difference between an IoT Edge and an I-IoT Edge?
   1. The IoT Edge has to deal with standard protocols, while the I-IoT Edge has to deal with legacy protocols
   2. The I-IoT Edge has to manage more signals than the IoT Edge
   3. The I-IoT Edge must deal with cybersecurity constraints, while the IoT Edge can be deployed without taking care of these

1. What is the best industrial data source for gathering the data to be sent to the cloud?
   1. PLC or DCS are the best since they manage all signals at a better sampling rate and resolution
   2. Historians are the best since they collect all data coming from all areas of the plant
   3. The best choice depends on the specific plant environment and the requirements of the specific use case

1. What is the main advantage of implementing the edge using an OPC Proxy?
   1. The OPC Proxy can act as an OPC concentrator, gathering the data from several OPC Classic or UA servers and making it available through a unique endpoint without the need to cross DCOM traffic between network boundaries
   2. The OPC Proxy can run on Windows boxes
   3. The OPC Proxy makes the data-acquisition chain simpler

1. Why do we often choose to gather data through an OPC Classic interface, rather than an OPC UA interface?
   1. Because OPC Classic makes a more efficient mechanism available for querying the data from the underlying device
   2. Because OPC Classic exposes a simpler information model
   3. Because we often have to deal with old devices, for which OPC UA is not available