In this post, we explained industrial network architecture, the components, the role of industrial network architecture, layers of industrial network architecture, the types, and the challenges.
Definition
Industrial network architecture is the design and structure of communication systems that connect devices and machinery in an industrial setting to enable control, monitoring, and automation. It includes the components like PLCs, field devices, and specific communication protocols, and requires high reliability and determinism. Common architectures can be based on various topologies like star, ring, and line, and are categorized by their function, such as sensor, control, or safety networks.
The Components of Industrial Network Architecture:
Physical components
Industrial Ethernet: The modern backbone for industrial networks, providing high-speed communication.
Switches and Routers: Hardware that connects devices, manages traffic, and directs data between different network segments.
Transmission Media: Cables (like twisted pair and fiber optics) and wireless technologies that physically carry the data.
Logical components
Protocols: The rules that govern how data is transmitted. Common examples include PROFINET, Ethernet/IP, and Modbus TCP/IP.
HMI (Human-Machine Interface): Graphical interfaces that allow operators to monitor and interact with industrial machinery.
Firewalls: Security devices that control and monitor incoming and outgoing traffic to protect the network from unauthorized access.
Gateways and Protocol Converters: Devices that translate between different network protocols, allowing dissimilar systems to communicate.
Network devices and endpoints
PLCs (Programmable Logic Controllers): Industrial computers that control and automate processes.
Sensors and Actuators: The devices that collect data (sensors) and execute commands (actuators).
SCADA (Supervisory Control and Data Acquisition): Systems used for monitoring and controlling industrial processes.
Architectural structure
Hierarchical Levels: Industrial networks are often structured in a pyramid with three levels:
Device Level: Field devices like sensors and actuators.
Control Level: PLCs, HMIs, and robots.
Enterprise Level: Higher-level software applications for planning and management.
Roles of Industrial Network Architecture:
Enables process control and automation: It connects sensors, actuators, and programmable logic controllers (PLCs) to allow for the automated monitoring and control of industrial processes.
Ensures reliability and determinism: Unlike standard IT networks, industrial networks are designed to be highly reliable and provide deterministic communication, meaning data arrives within a guaranteed time frame (e.g., milliseconds or microseconds). This is crucial for preventing costly and dangerous process interruptions.
Supports high-speed data transfer: Modern architectures using Industrial Ethernet facilitate high-speed communication and the transfer of large data packets, enabling more advanced applications and integration.
Provides security and data integrity: The architecture must protect against cyber threats and ensure the integrity of data transmitted across the network, which is vital for the security and stability of industrial operations.
Integrates with enterprise systems: It acts as the bridge to connect factory-level networks with company-wide systems like the internet and enterprise resource planning (ERP) systems, allowing for seamless data flow from the factory floor to business-level analysis.
Facilitates real-time analysis and decision-making: By providing instant access to data from the entire network, it supports timely analysis and quick decision-making for operations.
Offers flexibility and interoperability: Modern architectures allow for the integration of devices from different vendors and support multiple communication protocols, providing adaptability and ease of expansion.
Typical Layers of Industrial Network Architecture:
Device Level (Physical/Sensor Level): This is the foundation of the network, consisting of the physical devices directly involved in the production process, such as sensors, actuators, and field devices. It handles low-level, real-time data transmission.
Control Level: This layer connects the physical devices to higher-level control systems. It includes equipment like Programmable Logic Controllers (PLCs), Human-Machine Interfaces (HMIs), and SCADA systems that manage and automate the production process.
Aggregation or Backbone Layer: This layer acts as a bridge between the control and enterprise levels. It secures the connection between the lower-level networks and the corporate network, often using firewalls for segmentation.
Enterprise Level: This is the top layer, connecting the industrial network to the corporate business systems and enterprise-wide applications. It handles business logistics, planning, and data analysis for the entire facility.
Alternative Models
Some architectures use a model based on the standard networking models like the OSI model or TCP/IP model, which are divided into seven or four layers, respectively.
In these models, layers like the “Physical,” “Data Link,” and “Network” layers handle the foundational communication, while the “Transport,” “Session,” “Presentation,” and “Application” layers handle data transfer and user-facing functions.
Industrial networks will often adapt these models and combine layers, such as the TCP/IP’s four-layer model, to better suit their specific needs.
The Types of Industrial Network Architecture:
Sensor networks: The most basic and inexpensive type, used for monitoring and recording physical conditions.
Control networks: Used for tasks like process control and automation, often connecting controllers and other devices.
Safety buses: Networks specifically designed to handle safety-related functions, ensuring reliable operation.
Fieldbus networks: Networks that allow for high-speed and reliable communication between controllers and devices in the field. ControlNet, and Modbus.
Star: A central hub, like a switch, connects to multiple nodes. A failure in a connecting segment only affects that one node, but a hub failure can take down the entire network.
Ring: Nodes are connected in a circular fashion, often with self-healing capabilities to redirect traffic if a single link fails.
Bus: A single cable serves as the backbone, and multiple nodes are connected to it.
Hybrid: A combination of two or more topologies, such as mixing star and ring segments.
SCADA (Supervisory Control and Data Acquisition): A centralized system for monitoring and controlling industrial processes from a single platform.
DCS (Distributed Control System): Distributes control functions across multiple controllers to provide a more scalable and modular system.
IIoT (Industrial Internet of Things): Integrates a wide range of industrial devices to collect and analyze data, improving efficiency and enabling predictive maintenance.
The Challenges of Industrial Network Architecture:
Cybersecurity threats: The vast, interconnected nature of industrial networks creates a large attack surface, making them vulnerable to cyberattacks.
Data security: Sensitive data generated by devices is at risk of being breached.
Centralized control vulnerabilities: In some architectures like SDN, the core controller can be a single point of failure and a target for attacks.
Interoperability and integration
Proprietary systems: Many industrial systems rely on proprietary technologies and protocols, hindering communication between different devices and platforms.
OT/IT convergence: Integrating traditional operational technology with modern IT systems is a significant challenge.
Traffic convergence: It is difficult to converge different types of real-time and non-real-time traffic (like safety signals, vision data, and maintenance logs) onto a single network.
Performance and reliability
Low latency requirements: Industrial processes often have strict requirements for low latency and high reliability, which can be difficult to achieve under high traffic loads.
Performance bottlenecks: The performance of network equipment under new architectures like SDN needs to be validated to ensure it can handle the required speeds.
High implementation cost: The initial investment for hardware, software, and integration can be very high.
Data management: The sheer volume of data generated by IoT devices poses a significant challenge for storage, management, and analysis.
Complexity: Managing the complexity of a network that must meet both industrial and IT requirements is difficult.
Regulatory compliance: Many industries face complex regulations that require specific security and data integrity measures, adding another layer of complexity to network design.
Skills gap: There can be a lack of skilled personnel to manage and maintain the new and complex systems being implemented.
Conclusion
Industrial network architecture is the design of communication systems in industrial settings, built to connect machinery and control systems with requirements like reliability and determinism. It uses a hierarchical structure with specialized protocols (e.g., Fieldbus, Industrial Ethernet) to connect devices like PLCs and sensors at lower levels and enterprise systems at the top. The architecture segments networks to isolate different functions and uses technologies like Industrial IoT (IIoT) to collect and exchange data from physical assets.
READ: The Concept of Industrial Compliance Testing