OPC In Brief: Explaining Multiple Choice Questions
Discover OPC technology with simple explanations of multiple-choice questions. Ideal for quick understanding, this resource offers straightforward insights into OPC concepts, making it accessible to beginners and enthusiasts alike.
Which organization originally developed the OPC standard?
A. OLE for Process Control Foundation.
B. Microsoft.
C. Siemens.
D. Schneider Electric.
Answer: B
Explanation: The OPC standard was originally developed by Microsoft. It allowed a consistent method of accessing field data from various sources, primarily automation devices.
What does OPC DA stand for in OPC standards?
A. OPC Data Access.
B. OPC Device Architecture.
C. OPC Distributed Applications.
D. OPC Data Allocation.
Answer: A
Explanation: OPC DA stands for OPC Data Access, which is a group of client-server standards that provides specifications for exchanging real-time automation data between PCs.
OPC is based on which technology?
A. DCOM.
B. HTTP.
C. VPN.
D. SMTP.
Answer: A
Explanation: OPC is based on Distributed Component Object Model (DCOM) technology, a Microsoft technology that allows components of software to communicate in a networked environment.
What is OPC UA?
A. Universal Application.
B. Unified Architecture.
C. Unified Application.
D. Universal Architecture.
Answer: B
Explanation: OPC UA stands for Unified Architecture. It is a platform-independent service-oriented architecture that integrates all the functionality of the individual OPC Classic specifications into one extensible framework.
What is the main purpose of OPC?
A. To provide internet service.
B. To provide a uniform interface for controlling devices.
C. To provide a programming language for apps.
D. To provide error codes for computer programming.
Answer: B
Explanation: OPC is mainly used in the manufacturing industry for process control. It provides a uniform interface for controlling devices, allowing communication between devices from different manufacturers.
Which protocol does OPC UA use for data transport?
A. HTTP.
B. DCOM.
C. MQTT.
D. SMTP.
Answer: A
Explanation: OPC UA uses HTTP (Hypertext Transfer Protocol) for data transport.
Which data encoding does OPC UA use?
A. Binary.
B. XML.
C. JSON.
D. Both A and B.
Answer: D
Explanation: OPC UA uses both Binary and XML data encodings for flexibility and efficiency.
What does OPC HDA stand for?
A. OPC High Data Access.
B. OPC Historical Data Access.
C. OPC High Device Allocation.
D. OPC Historical Device Allocation.
Answer: B
Explanation: OPC HDA stands for OPC Historical Data Access, which enables access to historical process data.
What does OPC A&E stand for?
A. OPC Alarms & Exceptions.
B. OPC Alarms & Events.
C. OPC Applications & Exchanges.
D. OPC Applications & Events.
Answer: B
Explanation: OPC A&E stands for OPC Alarms & Events, which provides alarm and event notifications.
Is OPC UA platform-independent?
A. Yes.
B. No.
Answer: A
Explanation: OPC UA is platform-independent, meaning it can be used on any operating system, unlike the OPC Classic specifications.
What makes OPC UA more secure than OPC Classic?
A. It uses a more secure communication protocol.
B. It includes built-in security models.
C. It doesn’t use DCOM.
D. All of the above.
Answer: D
Explanation: OPC UA is considered more secure than OPC Classic because it uses a more secure communication protocol (HTTP), it includes built-in security models, and it does not rely on DCOM.
What is the role of a ‘client’ in OPC communication?
A. To request data.
B. To provide data.
C. To provide a communication channel.
D. To encrypt data.
Answer: A
Explanation: In OPC communication, the client’s role is to request data from the server.
What is the role of a ‘server’ in OPC communication?
A. To request data.
B. To provide data.
C. To provide a communication channel.
D. To encrypt data.
Answer: B
Explanation: In OPC communication, the server’s role is to provide data in response to the client’s request.
Which type of OPC standard provides access to real-time data?
A. OPC DA.
B. OPC UA.
C. OPC HDA.
D. OPC A&E.
Answer: A
Explanation: OPC DA (Data Access) provides access to real-time data.
Which type of OPC standard provides access to historical data?
A. OPC DA.
B. OPC UA.
C. OPC HDA.
D. OPC A&E.
Answer: C
Explanation: OPC HDA (Historical Data Access) provides access to historical data.
Which OPC standard allows complex data types?
A. OPC DA.
B. OPC UA.
C. OPC HDA.
D. OPC A&E.
Answer: B
Explanation: OPC UA (Unified Architecture) allows complex data types, making it a versatile option for industrial automation.
Which company developed the OPC standard?
A. Siemens.
B. Microsoft.
C. Schneider Electric.
D. IBM.
Answer: B
Explanation: The OPC standard was developed by Microsoft, which initially stood for “OLE for Process Control,” with OLE referring to “Object Linking and Embedding.”
Why was OPC UA introduced?
A. To replace HTTP with DCOM.
B. To integrate all the OPC Classic specifications.
C. To provide a less secure alternative to OPC.
D. To reduce the functionality of OPC.
Answer: B
Explanation: OPC UA was introduced to integrate all the OPC Classic specifications into one extensible framework.
Can OPC UA work over internet connections?
A. Yes.
B. No.
Answer: A
Explanation: OPC UA can work over internet connections, making it a flexible choice for various industrial settings.
What was the main limitation of OPC DA?
A. It could only access real-time data.
B. It could only access historical data.
C. It was platform-dependent.
D. Both A and C.
Answer: D
Explanation: OPC DA could only access real-time data and was platform-dependent, which were significant limitations.
Which technology did OPC originally rely on?
A. HTTP.
B. DCOM.
C. MQTT.
D. SMTP.
Answer: B
Explanation: OPC originally relied on DCOM (Distributed Component Object Model), a Microsoft technology.
Which data transport protocol does OPC UA use?
A. HTTP.
B. DCOM.
C. MQTT.
D. SMTP.
Answer: A
Explanation: OPC UA uses HTTP (Hypertext Transfer Protocol) for data transport.
What is one major advantage of OPC UA over OPC Classic?
A. It is platform-independent.
B. It uses DCOM.
C. It provides less security.
D. It has less functionality.
Answer: A
Explanation: One major advantage of OPC UA over OPC Classic is that it is platform-independent, meaning it can work on any operating system.
What kind of architecture does OPC UA use?
A. Monolithic architecture.
B. Microservices architecture.
C. Service-oriented architecture.
D. Layered architecture.
Answer: C
Explanation: OPC UA uses a service-oriented architecture, making it highly modular and scalable.
What kind of data can OPC transfer?
A. Real-time data.
B. Historical data.
C. Alarms and events.
D. All of the above.
Answer: D
Explanation: OPC can transfer real-time data, historical data, and alarms and events. The specific type of data depends on the OPC standard being used.
In OPC, the ‘server’ generally corresponds to which device?
A. Human-Machine Interface (HMI).
B. Programmable Logic Controller (PLC).
C. Personal Computer (PC).
D. Field device.
Answer: B
Explanation: In OPC communication, the server typically corresponds to a Programmable Logic Controller (PLC) or any field device that holds process data.
In which year was the OPC Foundation formed?
A. 1990.
B. 1995.
C. 2000.
D. 2005.
Answer: B
Explanation: The OPC Foundation was formed in 1995 to manage the OPC (OLE for Process Control) standard.
Which OPC standard deals with moving data from PLC to a database?
A. OPC DA.
B. OPC UA.
C. OPC HDA.
D. OPC XML-DA.
Answer: A
Explanation: OPC DA (Data Access) primarily deals with moving data from PLC to a database or any other applications.
Which of the following is a notable feature of OPC?
A. Ensuring data security.
B. Ensuring interoperability among different devices.
C. Both A and B.
D. Neither A nor B.
Answer: C
Explanation: OPC ensures both data security and interoperability among different devices from different manufacturers.
What was the original full form of OPC?
A. Object Process Control.
B. OLE for Process Control.
C. Open Platform Communications.
D. Operational Procedure Code.
Answer: B
Explanation: Originally, OPC stood for OLE (Object Linking and Embedding) for Process Control. However, it now stands for Open Platform Communications.
OPC XML-DA was created to solve which issue of OPC DA?
A. Dependency on DCOM.
B. Dependency on HTTP.
C. Dependency on TCP/IP.
D. Dependency on MQTT.
Answer: A
Explanation: OPC XML-DA was created to solve the issue of OPC DA’s dependency on DCOM (Distributed Component Object Model).
Which of the following technologies is used by OPC UA for secure communication?
A. SSL/TLS.
B. SSH.
C. PGP.
D. AES.
Answer: A
Explanation: OPC UA uses SSL/TLS (Secure Sockets Layer/Transport Layer Security) for secure communication.
OPC UA is based on which kind of architecture?
A. Client-Server.
B. Peer-to-Peer.
C. Master-Slave.
D. Both A and B.
Answer: A
Explanation: OPC UA is based on a client-server architecture.
Which organization is responsible for maintaining OPC standards?
A. The OPC Foundation.
B. Microsoft.
C. International Society of Automation.
D. National Institute of Standards and Technology.
Answer: A
Explanation: The OPC Foundation is the organization responsible for maintaining and developing OPC standards.
Which industry primarily uses OPC?
A. Healthcare.
B. Retail.
C. Manufacturing and Process Control.
D. Education.
Answer: C
Explanation: OPC is primarily used in the manufacturing and process
What is the primary function of OPC HDA?
A. To facilitate real-time data access.
B. To facilitate historical data access.
C. To manage alarms and events.
D. To support complex data types.
Answer: B
Explanation: OPC HDA (Historical Data Access) primarily facilitates access to historical process data.
What was the primary reason for developing OPC UA?
a. To simplify the OPC standard.
b. To provide a cross-platform framework.
c. To increase the dependency on DCOM.
d. To limit the data types supported.
Answer: B
Explanation: OPC UA (Unified Architecture) was developed to provide a platform-independent, service-oriented architecture that integrates all the functionality of the individual OPC Classic specifications.
Which standard uses the functionality of both OPC DA and OPC HDA?
A. OPC UA.
B. OPC XML-DA.
C. OPC A&E.
D. OPC .NET.
Answer: A
Explanation: OPC UA (Unified Architecture) uses the functionality of both OPC DA (Data Access) and OPC HDA (Historical Data Access), along with other OPC Classic specifications.
Which standard is considered the successor of OPC DA?
A. OPC UA.
B. OPC XML-DA.
C. OPC HDA.
D. OPC A&E.
Answer: B
Explanation: OPC XML-DA is considered the successor of OPC DA, providing similar functionality but with XML encoding and SOAP transport protocol instead of the DCOM used in OPC DA.
Which of the following is a component of an OPC system?
A. Server.
B. Client.
C. Both A and B.
D. Neither A nor B.
Answer: C
Explanation: An OPC system is made up of servers and clients. Servers provide data to clients, who request or subscribe to the data.
What technology does OPC UA replace DCOM with?
A. SOAP.
B. REST.
C. XML.
D. HTTP.
Answer: A
Explanation: OPC UA replaces DCOM with SOAP (Simple Object Access Protocol), a messaging protocol that allows programs running on different operating systems to communicate with each other.
Which security measures are in-built in OPC UA?
A. Authentication.
B. Encryption.
C. Authorization.
D. All of the above.
Answer: D
Explanation: OPC UA has in-built security measures that include authentication, encryption, and authorization.
What does OPC DX stand for?
A. OPC Data eXchange.
B. OPC Data XML.
C. OPC Device XML.
D. OPC Device eXchange.
Answer: A
Explanation: OPC DX (Data eXchange) is a standard for the exchange of data between OPC servers.
What does OPC .NET represent?
A. An OPC standard using .NET framework.
B. A library of OPC.
C. A data type in OPC.
D. A communication protocol in OPC.
Answer: A
Explanation: OPC .NET is an OPC specification that leverages the Microsoft .NET framework for easier and more efficient development of OPC clients and servers.
What technology does OPC A&E primarily deal with?
A. Real-time data.
B. Historical data.
C. Alarms and Events.
D. Data Exchange.
Answer: C
Explanation: OPC A&E (Alarms & Events) primarily deals with managing and communicating information about process alarms and events.
What is a ‘namespace’ in OPC UA?
A. A security feature.
B. A collection of identifiers for items on a server.
C. A communication protocol.
D. A data type.
Answer: B
Explanation: In OPC UA, a namespace is a collection of identifiers for items on a server. It provides a way to uniquely identify items and avoid naming conflicts.
Which of the following languages can be used to develop an OPC UA client?
A. C#.
B. Java.
C. Python.
D. All of the above.
Answer: D
Explanation: OPC UA clients can be developed in a variety of programming languages, including C#, Java, and Python.
What does ‘browsing’ mean in OPC?
A. Viewing the server’s namespace.
B. Viewing the client’s namespace.
C. Viewing the server’s security settings.
D. Viewing the client’s security settings.
Answer: A
Explanation: In OPC, ‘browsing’ refers to viewing the server’s namespace to identify the available items for data access.
What does OPC AE stand for?
A. OPC Automated Engine.
B. OPC Alarms and Events.
C. OPC Assembly Environment.
D. OPC Application Example.
Answer: B
Explanation: OPC AE stands for OPC Alarms and Events, a standard in OPC for dealing with alarms and events generated in the process.
What is one benefit of OPC UA’s platform-independence?
A. Increased security.
B. Flexibility across different operating systems.
C. Dependency on DCOM.
D. Limited data types.
Answer: B
Explanation: One benefit of OPC UA’s platform-independence is that it provides flexibility across different operating systems, making it adaptable to a variety of hardware and software environments.
Which OPC standard can work without a continuous network connection?
A. OPC DA.
B. OPC UA.
C. OPC HDA.
D. OPC A&E.
Answer: B
Explanation: OPC UA can work without a continuous network connection due to its session-based communication. If the connection is lost, the session can be reestablished without losing data.
What does ‘subscription’ mean in the context of OPC UA?
A. Paying a fee for using the OPC UA service.
B. Registering to receive updates about OPC UA.
C. A client requesting to be notified when specific data changes.
D. The process of connecting to an OPC UA server.
Answer: C
Explanation: In OPC UA, a ‘subscription’ refers to a client requesting to be notified when specific data changes. This mechanism reduces unnecessary data transfer by only sending updates when data changes.
What is the role of the OPC Compliance Test Tool (CTT)?
A. To verify if a product adheres to OPC standards.
B. To help develop OPC client and server applications.
C. To monitor the performance of an OPC server.
D. To simulate an OPC client for testing purposes.
Answer: A
Explanation: The OPC Compliance Test Tool (CTT) is used to verify if a product adheres to OPC standards. It runs a series of tests to ensure that the product is compliant with the specifications.
How does OPC DA handle timestamps for data?
A. It uses the server’s timestamp.
B. It uses the client’s timestamp.
C. It uses the timestamp from the data source.
D. It doesn’t support timestamps.
Answer: C
Explanation: OPC DA uses the timestamp from the data source. This ensures that the time associated with the data is the actual time at which the data value was recorded.
Which OPC specification supports web services?
A. OPC DA.
B. OPC HDA.
C. OPC UA.
D. OPC A&E.
Answer: C
Explanation: OPC UA supports web services, which allow for communication and data exchange over a network. This makes OPC UA flexible and adaptable to various networking situations.
What does ‘OLE’ stand for in the original full form of OPC?
A. Object Linking and Embedding.
B. Open Loop Exchange.
C. Operational Linkage Extension.
D. Object-Level Encryption.
Answer: A
Explanation: In the original full form of OPC, ‘OLE’ stands for Object Linking and Embedding, a technology developed by Microsoft.
What kind of data does OPC DX facilitate the exchange of?
A. Real-time data.
B. Historical data.
C. Alarms and events.
D. Configuration data.
Answer: D
Explanation: OPC DX (Data eXchange) facilitates the exchange of configuration data between different OPC servers, helping to improve interoperability.
What is the function of an OPC Bridge?
A. To connect two different OPC servers.
B. To connect an OPC client and server.
C. To secure data transmission in OPC.
D. To translate data between OPC and non-OPC systems.
Answer: A
Explanation: An OPC Bridge functions to connect two different OPC servers, allowing for the direct transfer of data between them without needing an intermediary client.
Which of the following is NOT a feature of OPC UA?
A. Platform independence.
B. Dependency on DCOM.
C. Built-in security features.
D. Support for complex data types.
Answer: B
Explanation: OPC UA does not depend on DCOM (Distributed Component Object Model). This was a limitation of earlier OPC standards, which OPC UA overcomes.
What does ‘DA’ stand for in OPC DA?
A. Data Acquisition.
B. Data Analysis.
C. Data Access.
D. Data Aggregation.
Answer: C
Explanation: In OPC DA, ‘DA’ stands for Data Access. It is an OPC standard for real-time data access.
How does OPC A&E handle alarms?
A. By notifying clients when an alarm state changes.
B. By storing alarm data in a database.
C. By stopping the process that caused the alarm.
D. By automatically resetting the alarm.
Answer: A
Explanation: OPC A&E (Alarms & Events) handles alarms by notifying clients when an alarm state changes. It provides detailed information about each alarm including its source, message, severity, and state.
How does OPC UA handle complex data types?
A. It simplifies them into basic data types.
B. It does not support complex data types.
C. It supports them directly.
D. It converts them into string format.
Answer: C
Explanation: OPC UA supports complex data types directly, allowing for the representation and exchange of more complex and detailed information.
Which of the following protocols can OPC UA use for transport?
A. HTTP.
B. MQTT.
C. AMQP.
D. All of the above.
Answer: D
Explanation: OPC UA can use various transport protocols, including HTTP (Hypertext Transfer Protocol), MQTT (Message Queuing Telemetry Transport), and AMQP (Advanced Message Queuing Protocol).
What is a ‘tag’ in the context of OPC?
A. A security feature.
B. An identifier for data items.
C. A type of data.
D. A protocol for data transmission.
Answer: B
Explanation: In the context of OPC, a ‘tag’ is an identifier for data items. Tags are used to reference and access specific data within an OPC server.
What does OPC BA stand for?
A. OPC Batch Automation.
B. OPC Binary Access.
C. OPC Base Architecture.
D. OPC Bridge Access.
Answer: A
Explanation: OPC BA stands for OPC Batch Automation. It’s a standard that facilitates the exchange of batch process control data.
Which OPC standard is platform-independent?
A. OPC DA.
B. OPC HDA.
C. OPC A&E.
D. OPC UA.
Answer: D
Explanation: OPC UA (Unified Architecture) is platform-independent, allowing it to work across various operating systems and hardware platforms.
How does OPC UA ensure data security?
A. By using a secure transport protocol.
B. By implementing authentication and authorization mechanisms.
C. By encrypting data during transmission.
D. All of the above.
Answer: D
Explanation: OPC UA ensures data security by using a secure transport protocol, implementing authentication and authorization mechanisms, and encrypting data during transmission.
Which OPC standard is based on XML and SOAP?
A. OPC DA.
B. OPC HDA.
C. OPC XML-DA.
D. OPC A&E.
Answer: C
Explanation: OPC XML-DA is based on XML (eXtensible Markup Language) and SOAP (Simple Object Access Protocol), making it more suitable for web-based communication.
What does OPC DSC stand for?
A. OPC Data Source Control.
B. OPC Device Set Configuration.
C. OPC Data Server Control.
D. OPC Data Structure Configurator.
Answer: B
Explanation: OPC DSC stands for OPC Device Set Configuration. It’s a standard that allows for the management of device set configurations.
What is the role of an OPC client in an OPC system?
A. To provide data to OPC servers.
B. To request or subscribe to data from OPC servers.
C. To manage the OPC system.
D. To secure the data transmission in the OPC system.
Answer: B
Explanation: In an OPC system, the role of an OPC client is to request or subscribe to data from OPC servers. The server provides the data as per the client’s request or subscription.
How does OPC UA ensure interoperability?
A. By using a platform-independent architecture.
B. By defining a standard set of data types.
C. By supporting different transport protocols.
D. All of the above.
Answer: D
Explanation: OPC UA ensures interoperability by using a platform-independent architecture, defining a standard set of data types, and supporting different transport protocols.
Which of the following is NOT a feature of OPC DA?
A. Real-time data access.
B. Support for complex data types.
C. Dependence on Microsoft DCOM.
D. Support for alarms and events.
Answer: D
Explanation: OPC DA does not inherently support alarms and events. This feature is primarily handled by OPC A&E.
Which of the following is a security feature of OPC UA?
A. Authentication.
B. Encryption.
C. Authorization.
D. All of the above.
Answer: D
Explanation: OPC UA includes various security features including authentication (verifying the identity of a user, system, or device), encryption (securing data during transmission), and authorization (defining access rights to resources).
How does OPC HDA handle data?
A. It provides real-time data.
B. It provides historical data.
C. It manages alarms and events.
D. It exchanges data between servers.
Answer: B
Explanation: OPC HDA (Historical Data Access) handles historical data, providing access to data that has been stored over time.
What does OPC DA provide?
A. Real-time data access.
B. Historical data access.
C. Alarms and events management.
D. Data exchange between servers.
Answer: A
Explanation: OPC DA (Data Access) provides real-time data access. It allows for the reading and writing of current data points in the system.
What does OPC DX provide?
A. Real-time data access.
B. Historical data access.
C. Alarms and events management.
D. Data exchange between servers.
Answer: D
Explanation: OPC DX (Data eXchange) provides the exchange of data between different OPC servers, thereby increasing interoperability.
What are ‘methods’ in OPC UA?
A. Procedures that can be executed on an OPC UA server.
B. The types of data that can be exchanged.
C. The communication protocols used.
D. The security measures implemented.
Answer: A
Explanation: In OPC UA, ‘methods’ refer to procedures that can be executed on an OPC UA server. They are defined in the OPC UA information model.
Which OPC standard allows for the management of batch processes?
A. OPC DA.
B. OPC HDA.
C. OPC A&E.
D. OPC BA.
Answer: D
Explanation: OPC BA (Batch Automation) allows for the management of batch processes, facilitating the exchange of batch process control data.
What is the primary function of OPC HDA?
A. To provide real-time data access.
B. To provide access to historical data.
C. To manage alarms and events.
D. To facilitate data exchange between OPC servers.
Answer: B
Explanation: The primary function of OPC HDA (Historical Data Access) is to provide access to historical data. It provides the means to store and retrieve historical process data.
What is ‘OPCEnum’ in OPC?
A. A tool for enumerating OPC servers.
B. A method for securing OPC communications.
C. An OPC standard for data access.
D. A data type in OPC.
Answer: A
Explanation: ‘OPCEnum’ is a service in OPC that allows for the enumeration of OPC servers on a machine. It helps clients to find available OPC servers.
Which OPC standard supports Data Access, Alarms & Events, and Historical Data Access all together?
A. OPC DA.
B. OPC HDA.
C. OPC A&E.
D. OPC UA.
Answer: D
Explanation: OPC UA (Unified Architecture) supports Data Access, Alarms & Events, and Historical Data Access all together. This combined functionality makes it more flexible and capable than the older, separate OPC standards.
Which communication mechanism does OPC DA rely on?
A. HTTP.
B. SOAP.
C. DCOM.
D. AMQP.
Answer: C
Explanation: OPC DA (Data Access) relies on DCOM (Distributed Component Object Model), a communication mechanism developed by Microsoft. This makes OPC DA primarily suitable for Windows-based systems.
Which OPC standard supports the transfer of files?
A. OPC DA.
B. OPC HDA.
C. OPC UA.
D. OPC A&E.
Answer: C
Explanation: OPC UA (Unified Architecture) supports the transfer of files, providing a mechanism for exchanging more complex data than just process variables.
Which protocol is NOT supported by OPC UA for data transmission?
A. HTTP.
B. MQTT.
C. SOAP.
D. FTP.
Answer: D
Explanation: OPC UA does not support FTP (File Transfer Protocol) for data transmission. It primarily uses HTTP, MQTT, and SOAP for communication.
What kind of data model does OPC UA use?
A. Hierarchical data model.
B. Network data model.
C. Relational data model.
D. Object-oriented data model.
Answer: D
Explanation: OPC UA uses an object-oriented data model. This model allows OPC UA to represent complex systems and data structures in an intuitive way.
What does OPC HDA provide?
A. Real-time data access.
B. Historical data access.
C. Alarms and events management.
D. Data exchange between servers.
Answer: B
Explanation: OPC HDA (Historical Data Access) provides access to historical data. It’s designed to retrieve, store, and analyze data from the past.
What are ‘nodes’ in the context of OPC UA?
A. Points of data transfer.
B. Data items in the OPC UA information model.
C. Parts of the network topology.
D. Components of the OPC UA server.
Answer: B
Explanation: In OPC UA, ‘nodes’ refer to data items in the OPC UA information model. Each node represents a piece of data or an object in the system.
What does ‘Browse’ mean in OPC UA?
A. To search for a specific piece of data.
B. To view the OPC UA server’s namespace.
C. To navigate the data structure of the OPC UA information model.
D. To request real-time data from the OPC UA server.
Answer: C
Explanation: ‘Browse’ in OPC UA refers to the ability to navigate the data structure of the OPC UA information model. It allows clients to discover the nodes and relationships between nodes in the server.
What is OPC AE primarily used for?
A. Real-time data access.
B. Historical data access.
C. Alarms and events management.
D. Data exchange between servers.
Answer: C
Explanation: OPC AE (Alarms & Events) is primarily used for the management of alarms and events. It provides the infrastructure for alarm notifications and tracking changes in state.
What is ‘OPC Compliance’?
A. A certification that an OPC product meets the OPC Foundation’s standards.
B. The process of implementing OPC in a system.
C. A measure of the performance of an OPC system.
D. A requirement for OPC servers to support all OPC standards.
Answer: A
Explanation: ‘OPC Compliance’ refers to a certification that an OPC product meets the standards defined by the OPC Foundation. It ensures that the product has implemented the OPC specifications correctly and will work reliably with other OPC-compliant products.
What is a common issue when working with OPC DA over a network?
A. Limited historical data access.
B. Difficulty in managing alarms and events.
C. Issues with DCOM configuration.
D. Inability to exchange data between servers.
Answer: C
Explanation: One of the most common issues when working with OPC DA over a network is difficulty with DCOM (Distributed Component Object Model) configuration. OPC DA relies on DCOM for communication, and improper DCOM settings can lead to various connectivity problems.
What might be a potential problem when implementing OPC UA?
A. Platform dependence.
B. Limited support for complex data types.
C. Complexity of the standard.
D. Inability to manage alarms and events.
Answer: C
Explanation: While OPC UA offers many benefits, its complexity can be a potential problem. The object-oriented nature and the vast capabilities of OPC UA can make implementation more challenging compared to simpler OPC standards.
Which is a common issue when using different OPC standards together?
A. Incompatible data models.
B. Lack of security features.
C. Different reliance on communication mechanisms.
D. All of the above.
Answer: D
Explanation: Using different OPC standards together can lead to issues such as incompatible data models, lack of unified security features, and different reliance on communication mechanisms. These differences can make integration challenging.
What is a common issue when dealing with OPC historical data?
A. Real-time data access.
B. Data storage and retrieval.
C. Alarms and events management.
D. Data exchange between servers.
Answer: B
Explanation: When dealing with OPC historical data, a common issue can be the storage and retrieval of data. Depending on the amount of data and the storage solutions used, it can be challenging to efficiently store and quickly retrieve historical data.
What could be a potential problem when integrating OPC with non-Windows platforms?
A. Inability to use DCOM.
B. Inability to handle complex data types.
C. Inability to manage alarms and events.
D. Inability to exchange data between servers.
Answer: A
Explanation: One of the potential problems when integrating OPC with non-Windows platforms is the inability to use DCOM (Distributed Component Object Model). OPC DA, for instance, relies on DCOM for communication, which is primarily supported by Windows. This can make integration with non-Windows platforms challenging.
What can cause delays in OPC DA data delivery?
A. Network congestion.
B. Inefficient data storage.
C. Misconfigured alarms.
D. Incorrect server enumeration.
Answer: A
Explanation: Network congestion can cause delays in OPC DA data delivery. As OPC DA is often used for real-time data access, any delays in the network can impact the timeliness of the data.
Which factor can affect the performance of an OPC system?
A. The speed of the network connection.
B. The number of OPC clients.
C. The amount of data being transferred.
D. All of the above.
Answer: D
Explanation: Several factors can affect the performance of an OPC system, including the speed of the network connection, the number of OPC clients, and the amount of data being transferred. Optimizing these factors can help ensure efficient operation.
What might be a challenge when transitioning from OPC Classic to OPC UA?
A. Learning a new programming model.
B. Ensuring backward compatibility.
C. Managing the increased security features.
D. All of the above.
Answer: D
Explanation: Transitioning from OPC Classic to OPC UA can present several challenges, including learning a new programming model, ensuring backward compatibility, and managing the increased security features of OPC UA.
Which issue might arise when using OPC over a wide area network (WAN)?
A. Difficulty with DCOM configuration.
B. High network latency affecting real-time data.
C. Difficulty managing alarms and events.
D. Inability to store historical data.
Answer: B
Explanation: When using OPC over a wide area network (WAN), high network latency can affect real-time data. This is particularly relevant for OPC DA, where timely data delivery is crucial.
What can be a potential security issue in OPC systems?
A. Insufficient authentication mechanisms.
B. Lack of encryption for data transmission.
C. Inadequate access control measures.
D. All of the above.
Answer: D
Explanation: OPC systems can have potential security issues such as insufficient authentication mechanisms, lack of encryption for data transmission, and inadequate access control measures. These issues can lead to unauthorized access, data breaches, and other security incidents.
What is the primary purpose of OPC standards?
A. To provide a universal data exchange standard for industrial automation.
B. To support real-time data access.
C. To manage alarms and events.
D. To provide historical data access.
Answer: A
Explanation: The primary purpose of OPC (OLE for Process Control) standards is to provide a universal data exchange standard for industrial automation. This includes various functionalities like real-time data access, alarm and event management, historical data access, and more, depending on the specific OPC standard.
What does OPC stand for?
A. Operational Procedure Control.
B. OLE for Process Control.
C. Object Protocol Communication.
D. Operational Platform Configuration.
Answer: B
Explanation: OPC stands for OLE for Process Control. It’s a set of standards specified by the OPC Foundation for industrial automation data exchange.
Which organization maintains the OPC standards?
A. The OPC Foundation.
B. The International Society of Automation.
C. The Automation Federation.
D. The Industrial Internet Consortium.
Answer: A
Explanation: The OPC Foundation is the organization that maintains the OPC standards. It’s a global consortium responsible for the development and maintenance of this standard.
What is OPC UA?
A. An OPC standard for real-time data access.
B. An OPC standard for alarms and events management.
C. An OPC standard that unifies the features of other OPC standards.
D. An OPC standard for data exchange between servers.
Answer: C
Explanation: OPC UA (Unified Architecture) is an OPC standard that unifies the features of other OPC standards. It provides a comprehensive and secure infrastructure for industrial automation data exchange.
What does OPC DA enable?
A. Real-time data access.
B. Historical data access.
C. Alarms and events management.
D. Data exchange between servers.
Answer: A
Explanation: OPC DA (Data Access) primarily enables real-time data access. It allows OPC clients to read and write current data points in an industrial automation system.
What does DCOM stand for, and why is it significant in OPC DA?
A. Distributed Component Object Model – It’s the communication mechanism that OPC DA relies on.
B. Direct Communication Object Model – It’s the data model used by OPC DA.
C. Data Control Object Model – It’s the security feature implemented in OPC DA.
D. Device Configuration Object Model – It’s the method for device configuration in OPC DA.
Answer: A
Explanation: DCOM stands for Distributed Component Object Model. It’s a communication mechanism developed by Microsoft. OPC DA (Data Access) relies on DCOM for communication, making it primarily suitable for Windows-based systems.
How does OPC UA handle security?
A. Through authentication, encryption, and authorization.
B. By relying on external security measures.
C. By using secure tokens.
D. Through firewall configurations.
Answer: A
Explanation: OPC UA handles security through a comprehensive security model that includes authentication (verifying the identity of a user, system, or device), encryption (securing data during transmission), and authorization (defining access rights to resources).
What does OPC A&E enable?
A. Real-time data access.
B. Historical data access.
C. Alarms and events management.
D. Data exchange between servers.
Answer: C
Explanation: OPC A&E (Alarms & Events) enables alarms and events management. It provides the infrastructure for event notifications and tracking changes in state in an industrial automation system.
What is the role of OPC HDA?
A. It enables real-time data access.
B. It enables historical data access.
C. It manages alarms and events.
D. It facilitates data exchange between servers.
Answer: B
Explanation: OPC HDA (Historical Data Access) has the role of enabling access to historical data. It provides the means to retrieve, store, and analyze data from the past.
What are the main advantages of OPC UA over OPC Classic?
A. Platform independence and enhanced security features.
B. Real-time data access and alarms and events management.
C. Historical data access and data exchange between servers.
D. All of the above.
Answer: A
Explanation: The main advantages of OPC UA (Unified Architecture) over OPC Classic are its platform independence and enhanced security features. Unlike OPC Classic standards like OPC DA, OPC UA does not rely on DCOM and can be implemented on various operating systems. Moreover, OPC UA includes a comprehensive security model not present in OPC Classic.
What is an OPC client?
A. Software that requests and receives data from an OPC server.
B. Software that provides data to OPC clients.
C. A physical device in an OPC system.
D. A protocol used in OPC communication.
Answer: A
Explanation: An OPC client is software that communicates with an OPC server to request and receive data. This data may come from various sources, like PLCs, RTUs, or other industrial devices, and is provided to the client via the OPC server.
What is an OPC server?
A. Software that requests and receives data from an OPC client.
B. Software that provides data to OPC clients.
C. A physical device in an OPC system.
D. A protocol used in OPC communication.
Answer: B
Explanation: An OPC server is software that communicates with OPC clients to provide data. It acts as a middleware between the clients and the data sources, translating the specific protocols of the industrial devices into the standard OPC format.
How do OPC clients and servers communicate?
A. Via DCOM.
B. Via HTTP.
C. Depending on the OPC standard, it could be DCOM or other protocols like HTTP or HTTPS.
D. Via OPC-specific communication protocols.
Answer: C
Explanation: The communication mechanism between OPC clients and servers depends on the OPC standard. OPC Classic standards, like OPC DA, use DCOM (Distributed Component Object Model), whereas OPC UA can use various protocols including HTTP, HTTPS, and more.
What role does an OPC Server play in industrial automation?
A. It controls physical devices directly.
B. It translates the device-specific protocols into the standard OPC format.
C. It monitors the network for security threats.
D. It stores historical data for analysis.
Answer: B
Explanation: In industrial automation, an OPC server plays the crucial role of a middleware. It communicates with various industrial devices, each possibly using its own protocol, and translates this device-specific data into the standard OPC format, which can be understood by OPC clients.
How does an OPC client software benefit industrial systems?
A. It enables real-time control of physical devices.
B. It allows access to data from different devices using a standard protocol.
C. It provides encryption for data transmission.
D. It stores and retrieves historical data.
Answer: B
Explanation: OPC client software provides a significant benefit to industrial systems by allowing access to data from different devices using a standard protocol. This interoperability simplifies integration, eliminates the need for custom drivers for each device, and enhances overall system efficiency.
What is the purpose of OPC bridging software?
A. To enable communication between two OPC servers.
B. To secure data transmission in OPC communication.
C. To provide a graphical interface for OPC systems.
D. To control physical devices in an OPC system.
Answer: A
Explanation: OPC bridging software is designed to enable communication between two OPC servers. This can be particularly useful in situations where data needs to be shared between different OPC systems, perhaps operating under different OPC standards or located on different networks.
What is OPC tunneling and why is it used?
A. It’s a method for securing OPC communication, used to protect data integrity.
B. It’s a method for transmitting OPC data over a network, used to overcome DCOM limitations.
C. It’s a method for storing OPC data, used to optimize storage space.
D. It’s a method for visualizing OPC data, used to improve user interface.
Answer: B
Explanation: OPC tunneling is a method for transmitting OPC data over a network. It’s primarily used to overcome the limitations of DCOM (Distributed Component Object Model), which can be challenging to configure, particularly in complex networks. OPC tunneling can provide a more reliable and easier-to-implement solution.
What does an OPC historian software do?
A. It provides real-time data access.
B. It manages alarms and events.
C. It collects, stores, and retrieves historical process data.
D. It enables communication between OPC servers.
Answer: C
Explanation: OPC historian software is designed to collect, store, and retrieve historical process data. It provides access to past data for analysis, reporting, and optimization purposes.
How can OPC redundancy be achieved?
A. By implementing multiple OPC clients for each OPC server.
B. By implementing OPC bridging software.
C. By implementing OPC tunneling software.
D. By implementing multiple OPC servers for each OPC client.
Answer: D
Explanation: OPC redundancy can be achieved by implementing multiple OPC servers for each OPC client. In this setup, if one OPC server fails, the OPC client can continue to operate by switching to another OPC server, thus ensuring system reliability and availability.
What is an OPC Wrapper?
A. It’s software that converts OPC communication to another protocol.
B. It’s software that converts non-OPC communication to OPC protocol.
C. It’s software that encrypts OPC communication for security.
D. It’s software that compresses OPC data for efficient storage.
Answer: B
Explanation: An OPC Wrapper is a type of software that takes non-OPC communication (typically a device-specific or system-specific protocol) and “wraps” it in OPC communication. This allows non-OPC data sources to be accessed by OPC clients, thereby extending interoperability.
Which OPC standard would be most suitable for transporting data over a restricted or low-bandwidth network?
A. OPC DA.
B. OPC UA.
C. OPC HDA.
D. OPC A&E.
Answer: B
Explanation: OPC UA (Unified Architecture) would be most suitable for transporting data over a restricted or low-bandwidth network. OPC UA can work with binary encoding, which is more compact than the XML encoding used by OPC Classic, making it more efficient for limited-bandwidth scenarios.
What does an OPC Simulator do?
A. It replicates the functionality of an OPC client.
B. It replicates the functionality of an OPC server.
C. It tests the security of an OPC system.
D. It visualizes the data in an OPC system.
Answer: B
Explanation: An OPC Simulator replicates the functionality of an OPC server. This can be useful in various scenarios, such as when developing and testing OPC client software or when training users, without the need for an actual OPC server or physical devices.
What is the purpose of an OPC Router?
A. To direct network traffic in an OPC system.
B. To facilitate the transfer of data between different OPC servers and/or clients.
C. To encrypt OPC communication.
D. To store historical OPC data.
Answer: B
Explanation: An OPC Router is used to facilitate the transfer of data between different OPC servers and/or clients. It enables interoperability between different OPC systems, possibly using different OPC standards or located on different networks.
How does OPC DX (Data eXchange) differ from other OPC standards?
A. It enables real-time data access.
B. It manages alarms and events.
C. It enables data exchange between OPC servers.
D. It provides historical data access.
Answer: C
Explanation: OPC DX (Data eXchange) is an OPC standard that differs from others by its focus on enabling data exchange between OPC servers. This provides a standard way for OPC servers to share data with each other directly, without the need for an OPC client as an intermediary.
Which technology is OPC based on?
A. OLE (Object Linking and Embedding).
B. MQTT (Message Queuing Telemetry Transport).
C. REST (Representational State Transfer).
D. SOAP (Simple Object Access Protocol).
Answer: A
Explanation: OPC (OLE for Process Control) is based on OLE (Object Linking and Embedding), a technology developed by Microsoft. More specifically, OPC Classic is based on the component object model (COM) and distributed component object model (DCOM) technologies, both of which are extensions of OLE.
Which programming languages can be used to develop OPC client applications?
A. Only C and C++.
B. Only languages that run on the .NET Framework.
C. Any language that supports the creation of COM/DCOM or HTTP/HTTPS clients, depending on the OPC standard.
D. Only Java.
Answer: C
Explanation: The development of OPC client applications can be done in any programming language that supports the creation of COM/DCOM clients (for OPC Classic) or HTTP/HTTPS clients (for OPC UA). This includes languages like C, C++, Java, Python, and others, making OPC a very versatile standard.
What is the role of an OPC Broker?
A. It provides real-time data access.
B. It manages alarms and events.
C. It enables data exchange between OPC servers.
D. It facilitates the communication between OPC clients and servers, providing features like load balancing and failover.
Answer: D
Explanation: An OPC Broker facilitates the communication between OPC clients and servers. It often provides features like load balancing, which helps distribute the workload evenly across multiple OPC servers, and failover, which allows the system to continue operating even if one or more OPC servers fail.
In the context of OPC, what is a tag?
A. A label used to identify data from a specific source.
B. A code used to secure OPC communication.
C. A tool used to manage OPC servers.
D. A protocol used in OPC communication.
Answer: A
Explanation: In the context of OPC, a tag is a label used to identify data from a specific source, such as a sensor or an actuator in an industrial process. This helps in easily identifying and managing data within an OPC system.
What type of systems typically employ OPC technology?
A. Consumer electronics.
B. E-commerce platforms.
C. Industrial automation systems.
D. Spacecraft control systems.
Answer: C
Explanation: OPC technology is typically employed in industrial automation systems. It is designed to provide a reliable, efficient, and standard method for different software applications to communicate with industrial hardware devices.
Which OPC specification would you use for real-time, high-speed data transfer?
A. OPC DA.
B. OPC UA.
C. OPC HDA.
D. OPC A&E.
Answer: A
Explanation: OPC DA (Data Access) is the OPC specification designed for real-time, high-speed data transfer. It focuses on providing quick access to current data from the devices in an industrial system.
What does OPC stand for in the context of industrial automation?
A. Official Protocol Communication.
B. Optimal Process Control.
C. Ole for Process Control.
D. Open Platform Communications.
Answer: C
Explanation: In the context of industrial automation, OPC stands for ‘Ole for Process Control’. It is a series of standards and specifications for industrial telecommunication.
What type of data does OPC A&E handle?
A. Real-time data.
B. Historical data.
C. Alarm and Event data.
D. Network traffic data.
Answer: C
Explanation: OPC A&E (Alarms and Events) is designed to handle alarm and event data.
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