Communication Principles – Module 5 Exam Answers

Communication Principles – Module 5 Exam Answers

This document provides detailed answers to the Module 5 exam answers on Communication Principles, designed to help learners verify their understanding and improve their knowledge. The answers cover key topics such as effective message structuring, active listening techniques, the role of non-verbal communication, and selecting appropriate communication channels. Each response has been crafted to align with the module’s objectives, offering clear explanations and examples to ensure you grasp the concepts thoroughly.

1. Why is it important to use the same standards in manufacturing Programmable Logic Controllers (PLCs), Variable Frequency Drives (VFDs), Human-Machine Interfaces (HMIs), and other devices connected to the Industrial Automation and Control System (IACS) network?

• It reduces the cost of manufacturing.
• It ensures reliable communication between devices on the IACS network.
• It allows for compatibility with the Internet.
• It simplifies the installation process.

Using the same standards in manufacturing PLCs, VFDs, HMIs, and other IACS devices ensures that they can communicate reliably on the IACS network. This standardization promotes compatibility and interoperability, leading to a more reliable and efficient industrial automation system.

The correct answer is:

It ensures reliable communication between devices on the IACS network.

Using the same standards in manufacturing Programmable Logic Controllers (PLCs), Variable Frequency Drives (VFDs), Human-Machine Interfaces (HMIs), and other devices connected to the Industrial Automation and Control System (IACS) network is critical for ensuring interoperability and reliable communication. Standardization ensures that devices from different manufacturers can effectively exchange data and operate seamlessly, reducing downtime and enhancing the overall efficiency of the automation system.

2. Why are organizations like IEC, ANSI/RIA, ISO, and IEEE considered excellent choices for developing Industrial Automation and Control System (IACS) communications standards?

• They prioritize cost-effectiveness in standards development.
• They have expertise in considering the unique characteristics and requirements of IACS networks.
• They primarily work on Internet-related standards.
• They focus on developing IT network standards.

Organizations like IEC, ANSI/RIA, ISO, and IEEE are considered excellent choices for developing IACS communications standards because they have expertise in understanding and addressing the specific characteristics and requirements of Industrial Automation and Control System (IACS) networks. These organizations focus on the nuances of IACS networks, often involving real-time communication and other unique considerations.

The correct answer is:

They have expertise in considering the unique characteristics and requirements of IACS networks.

Organizations like IEC (International Electrotechnical Commission), ANSI/RIA (American National Standards Institute/Robotics Industry Association), ISO (International Organization for Standardization), and IEEE (Institute of Electrical and Electronics Engineers) are well-suited for developing Industrial Automation and Control System (IACS) communication standards because they specialize in addressing the specific needs of these systems. This includes considerations such as real-time communication, reliability, scalability, safety, and interoperability, which are crucial for industrial environments.

3. What is the key difference between the OSI and TCP/IP models?

• The TCP/IP model has more layers than the OSI model.
• The OSI model combines the Data Link and Physical layers into one, while the TCP/IP model keeps them separate.
• The TCP/IP model combines the Application, Presentation, and Session layers, while the OSI model keeps them separate.
• The OSI model is harder to troubleshoot because it has more layers.

The OSI model consists of seven layers, including the Application, Presentation, and Session layers as separate entities. In contrast, the TCP/IP model compresses these three layers into one Application layer. This compression simplifies the TCP/IP model into four layers: Application, Transport, Internet, and Network Access.

The correct answer is:

The TCP/IP model combines the Application, Presentation, and Session layers, while the OSI model keeps them separate.

The OSI model is a seven-layer framework where the Application, Presentation, and Session layers are distinct, focusing on specific functionalities like data formatting, session management, and application-level services. The TCP/IP model, however, consolidates these three layers into a single Application layer, making the model simpler and more directly aligned with real-world networking protocols. This results in the TCP/IP model having four layers: Application, Transport, Internet, and Network Access.

4. What is the primary purpose of the Fieldbus model in industrial communication and control systems?

• To empower distributed control and reduce wiring complexity
• To replace digital networks with traditional wiring
• To increase point-to-point wiring complexity
• To limit flexibility and prevent real-time monitoring

The Fieldbus model in industrial communication and control systems is designed to replace traditional point-to-point wiring with a digital network. Its primary purpose is to empower distributed control, reduce wiring complexity, and enable real-time monitoring and control.

The correct answer is:

To empower distributed control and reduce wiring complexity

The Fieldbus model in industrial communication and control systems replaces traditional point-to-point wiring with a digital network that connects multiple devices. This approach reduces the complexity and cost of wiring, enables distributed control by allowing devices to communicate directly, and supports real-time monitoring and control, which is crucial for modern industrial automation systems.

5. Which network topologies are most effective with the Fieldbus model?

• Only daisy-chain and star
• Only branch and star
• Daisy-chain, star, branch, tree, and ring
• Only ring and tree

The Fieldbus model uses various network topologies, including daisy chain, star, branch, tree, and ring. It provides a bidirectional communication protocol for real-time closed-loop control between intelligent field instruments and host systems, ensuring between the physical layer and the network and transport layers, ensuring reliable and efficient communication between devices.

The correct answer is:

Daisy-chain, star, branch, tree, and ring

The Fieldbus model supports multiple network topologies such as daisy-chain, star, branch, tree, and ring to enable flexible and efficient communication. These topologies provide adaptability to different industrial environments, allowing for bidirectional communication between intelligent field instruments and host systems. This versatility ensures reliable and efficient real-time closed-loop control, which is essential for industrial automation and control systems.

6. What does the physical layer of the Fieldbus model specify?

• Only transmission rates
• Transmission rates, signal modulation methods, cable types, and connector types
• Only cable types and connector types
• Framing data packets, error checking, and flow control

The physical layer of the Fieldbus model governs or specifies various aspects, including transmission rates, signal modulation methods, cable types, and connector types. This ensures reliable data exchange between field devices and control systems.

The correct answer is:

Transmission rates, signal modulation methods, cable types, and connector types

The physical layer of the Fieldbus model defines the foundational aspects of communication, such as transmission rates, signal modulation methods, cable types, and connector types. These specifications ensure that the hardware components can reliably exchange data, providing the necessary infrastructure for communication between field devices and control systems in industrial automation networks.

7. What is the primary responsibility of the data link layer in the Fieldbus model?

• Framing data packets, error checking, and flow control
• Managing physical layer specifications
• Prioritizing data packets based on content
• Routing data between devices

The data link layer in the Fieldbus model is responsible for tasks such as framing data packets, error checking, and flow control. It acts as an intermediary between the physical layer and the network and transport layers, ensuring reliable and efficient communication between devices.

The correct answer is:

Framing data packets, error checking, and flow control

The data link layer in the Fieldbus model is responsible for managing framing, error detection and correction, and flow control. It ensures that data is transmitted reliably over the physical medium by detecting and correcting errors and managing data flow to prevent congestion. This layer serves as the bridge between the physical layer and higher communication layers, ensuring smooth and efficient data exchange in industrial systems.

8. What is the primary role of the Fieldbus Access Sublayer (FAS) in the data link layer of the Fieldbus model?

• Prioritizing data packets based on content
• Managing access to the communication medium
• Routing data between devices
• Framing data packets and error-checking

The Fieldbus Access Sublayer (FAS) manages access to the communication medium in a multi-access environment. It coordinates the transmission of data frames among field devices, ensuring fair and efficient network bandwidth utilization.

The correct answer is:

Managing access to the communication medium

The Fieldbus Access Sublayer (FAS) within the data link layer of the Fieldbus model is responsible for managing access to the shared communication medium in a multi-access environment. It ensures that data frames are transmitted efficiently and fairly among field devices, avoiding collisions and optimizing network bandwidth utilization for smooth and reliable communication in industrial networks.

9. Historically, how did automation and control protocols operate on dedicated OT networks?

• Utilizing Ethernet for communication
• Using fiber-optic cables
• Exclusively on dedicated wireless networks
• Following the RS-232 or RS-485 serial communication specifications

Historically, automation and control protocols often operated on dedicated OT networks, and many of them used two-wire media or followed the RS-232 or RS-485 serial communication specifications.

The correct answer is:

Following the RS-232 or RS-485 serial communication specifications

Historically, automation and control protocols operated on dedicated Operational Technology (OT) networks using RS-232 or RS-485 serial communication specifications. These protocols relied on two-wire media for reliable, point-to-point, or multi-drop communication. These serial communication methods were widely used in early industrial systems due to their simplicity and robustness, enabling effective data transfer between control devices and field instruments.

10. In Level 0 (cell zone), what are some commonly used analog standards for carrying signals between controllers, sensors, and actuators?

• Wi-Fi
• 4-20 milliamp (mA) current standard
• RS-232
• Ethernet

In Level 0 (cell zone), analog standards are often used, such as the 0-10V DC voltage input output range and the 4-20 milliamp (ma) current standard, electrical current-related standards are probably the most widely used in Level 0 to carry the analog signals between the controllers and the sensors and actuators.

The correct answer is:

4-20 milliamp (mA) current standard

In Level 0 (cell zone), commonly used analog standards include the 4-20 milliamp (mA) current standard and the 0-10V DC voltage range. These standards are widely used to transmit analog signals between controllers, sensors, and actuators because they are reliable, immune to noise, and can carry signals over long distances with minimal loss. Among these, the 4-20 mA current standard is especially popular due to its simplicity and robustness in industrial environments.

11. Which industrial communication protocols are based on the producer-consumer paradigm?

• EtherNET/IP and Open Smart Grid Protocol (OSGP)
• PROFINET
• Common Industrial Protocol (CIP) and PROFINET
• Modbus

The Common Industrial Protocol (CIP) and PROFINET are based on the producer-consumer paradigm. Modbus, on the other hand, uses a client-server communication model.

The correct answer is:

Common Industrial Protocol (CIP) and PROFINET

The Common Industrial Protocol (CIP) and PROFINET operate based on the producer-consumer paradigm, where devices produce data that is consumed by multiple other devices without requiring a direct query. This approach allows for more efficient and flexible data exchange in real-time industrial automation systems. In contrast, Modbus uses a client-server (or master-slave) communication model.

12. Which industrial communication protocol operates in a deterministic ring topology and focuses on short cycle times?

• DeviceNet
• EtherCAT
• CAN (Controller Area Network)
• EtherNet/IP

EtherCAT (Ethernet for Control Automation Technology) operates in a deterministic ring topology and is focused on short cycle times, often less than or equal to 100 microseconds.

The correct answer is:

EtherCAT

EtherCAT (Ethernet for Control Automation Technology) operates in a deterministic ring topology and is specifically designed for short cycle times, often less than or equal to 100 microseconds. This makes it highly suitable for real-time industrial automation applications where precise and rapid communication is critical. Its unique frame processing method allows for efficient data exchange, even in complex systems with many devices.

13. Which serial communication protocol can support a multi-point network where multiple devices and drivers can operate simultaneously?

• EtherNet/IP
• RS-485
• RS-232
• RS-422

RS-485 is a serial communication protocol that supports a multi-point network, allowing multiple devices and drivers to operate simultaneously.

The correct answer is:

RS-485

RS-485 is a serial communication protocol that supports multi-point networks, enabling multiple devices and drivers to operate on the same communication bus simultaneously. Its differential signaling allows for greater noise immunity and longer communication distances compared to RS-232, making it ideal for industrial environments where multiple devices need to communicate efficiently.

14. Which American National Standards Institute (ANSI) standard provides a common data structure and descriptors for data transfer to and from utility end devices like smart meters?

• ANSI C12.16
• ANSI C12.19
• ANSI C12.21
• ANSI C12.22

ANSI C12.19-202x is a standard published by the American National Standards Institute (ANSI) that provides a common data structure and descriptors for data transfer to and from utility end devices such as smart meters.

The correct answer is:

ANSI C12.19

ANSI C12.19 is the standard established by the American National Standards Institute (ANSI) that defines a common data structure and descriptors for data transfer between utility end devices, such as smart meters, and their management systems. This standard facilitates interoperability and efficient communication in utility and energy management systems.

15. Which IEC 61850 mechanism is specifically designed for exchanging status messages between Intelligent Electronic Devices (IEDs) in power substations, encapsulating data directly into Ethernet frames, and having fast transfer characteristics?

• Precision Time Protocol (PTP)
• Network Time Protocol (NTP) and Simple Network Time Protocol (SNTP)
• GOOSE
• Sampled Values (SV)
• GSSE