Introduction

Programmable Logic Controllers (PLCs) are the backbone of modern industrial automation systems. From assembly lines and packaging machines to water treatment facilities and power plants, PLCs control critical processes that require fast and reliable communication.

As factories adopt Industry 4.0 technologies, PLC networks are becoming more complex and interconnected. Reliable networking infrastructure is essential to ensure seamless communication between controllers, sensors, HMIs, SCADA systems, and industrial computers.

An Industrial Ethernet Switch for PLC Networks provides the performance, stability, and redundancy required for these mission-critical applications.

This guide explains how industrial Ethernet switches support PLC communications, what features matter most, and how to choose the right switch for your automation network.

What Is a PLC Network?

A PLC network connects automation devices to exchange data and control industrial processes.

Typical devices include:

• PLCs

• Remote I/O modules

• HMIs

• Industrial PCs

• SCADA servers

• Variable Frequency Drives (VFDs)

• Sensors and actuators

• Robotics systems

The network allows these devices to communicate in real time and coordinate production activities.

Why PLC Networks Require Industrial Ethernet Switches

Unlike office networks, industrial automation systems often operate:

• 24/7

• In harsh environments

• With strict latency requirements

• Under high reliability expectations

Industrial Ethernet switches are specifically designed to meet these challenges.

Benefits include:

• Stable communication

• Low latency

• EMI resistance

• Wide temperature operation

• Long product lifecycle

Common PLC Communication Protocols

Industrial Ethernet switches support a wide range of industrial protocols.

PROFINET

Commonly used with industrial PLC systems.

Advantages:

• Real-time communication

• High reliability

• Industrial automation support

EtherNet/IP

Widely used in factory automation.

Supports:

• Controller communication

• Device integration

• Real-time data exchange

Modbus TCP

One of the most popular industrial Ethernet protocols.

Benefits:

• Simple implementation

• Broad compatibility

• Cost-effective integration

EtherCAT

Designed for high-speed industrial control.

Ideal for:

• Motion control

• Robotics

• Precision manufacturing

Key Functions of an Industrial Ethernet Switch in PLC Networks

Device Connectivity

The switch serves as a communication hub connecting:

• PLCs

• HMIs

• SCADA systems

• Industrial PCs

This ensures reliable data exchange throughout the network.

Traffic Management

Managed industrial switches can prioritize critical automation traffic.

Benefits:

• Reduced latency

• Improved responsiveness

• Better system stability

Network Expansion

Industrial switches make it easy to add:

• Additional controllers

• New production lines

• More monitoring equipment

without redesigning the entire network.

Managed vs Unmanaged PLC Network Switches

Unmanaged Switches

Advantages:

• Plug-and-play installation

• Lower cost

• Simple operation

Suitable for:

• Small machine networks

• Standalone equipment

Managed Switches

Advantages:

• VLAN support

• QoS

• SNMP monitoring

• Network diagnostics

• Redundancy protocols

Suitable for:

• Large factories

• Multiple production lines

• Mission-critical automation systems

For most modern PLC networks, managed switches are recommended.

Why Gigabit Ethernet Matters

Older automation systems often relied on 100Mbps networks.

However, today's industrial environments include:

• Machine vision systems

• Industrial IoT devices

• Real-time analytics

• High-resolution monitoring

Gigabit Ethernet provides:

• 10× higher bandwidth

• Faster response times

• Better scalability

A Gigabit Industrial Ethernet Switch is now the preferred choice for new installations.

Importance of Redundancy in PLC Networks

Downtime in industrial environments can be extremely expensive.

Industrial managed switches often support:

• ERPS

• RSTP

• STP

These redundancy technologies allow traffic to automatically reroute if a connection fails.

Benefits:

• Reduced downtime

• Improved reliability

• Continuous production

Fiber Connectivity for Large Facilities

Many manufacturing sites span multiple buildings.

Copper Ethernet limitations:

• Maximum distance: 100 meters

Industrial switches with SFP fiber ports support:

• Long-distance communication

• EMI immunity

• High-speed backbone connections

Fiber is commonly used between:

• Production buildings

• Warehouses

• Control rooms

Critical Features to Look For

Wide Temperature Range

Recommended:

-40°C to 75°C

Supports operation in harsh industrial environments.

DIN Rail Mounting

Allows easy installation inside industrial control cabinets.

Dual Power Inputs

Provides power redundancy.

Important for:

• Critical automation systems

• Continuous production environments

Surge Protection

Protects equipment from electrical disturbances.

Fanless Design

Benefits include:

• Reduced maintenance

• Longer service life

• Improved reliability

PLC Network Topologies

Star Topology

Most common industrial architecture.

Advantages:

• Easy troubleshooting

• Flexible expansion

Example:

Each PLC connects directly to a central switch.

Ring Topology

Provides network redundancy.

Advantages:

• High availability

• Fast recovery

Common in:

• Large manufacturing facilities

• Critical production systems

Line Topology

Used in smaller machine networks.

Advantages:

• Reduced cabling

• Simple deployment

Industrial Ethernet Switch Applications

Manufacturing Plants

Supports:

• Production line automation

• Machine communication

• Process monitoring

Food and Beverage Industry

Supports:

• Packaging systems

• Conveyor controls

• Quality inspection systems

Water Treatment Facilities

Supports:

• Pump control

• Monitoring systems

• Remote operations

Energy and Utilities

Supports:

• Substation automation

• Renewable energy monitoring

• Power distribution systems

Common Mistakes When Designing PLC Networks

Using Commercial Switches

Commercial switches may not survive harsh industrial environments.

Ignoring Redundancy

Single points of failure increase operational risk.

Underestimating Future Growth

Additional production equipment often requires more network capacity.

Choosing Insufficient Bandwidth

Future automation projects may require Gigabit infrastructure.

Best Practices for PLC Network Deployment

Use Managed Industrial Switches

For improved visibility and control.

Separate Critical Traffic

Use VLANs to isolate automation traffic.

Deploy Redundant Networks

Minimize production interruptions.

Monitor Network Performance

Use SNMP and diagnostic tools.

Plan for Expansion

Leave spare ports and bandwidth capacity.

Future Trends in PLC Networking

Industrial automation continues to evolve with:

• Industry 4.0

• Smart factories

• Industrial IoT

• Machine learning

• Edge computing

These technologies demand:

• Higher bandwidth

• Lower latency

• Greater reliability

Industrial Ethernet switches will remain a foundational component of modern PLC networks.

Conclusion

An Industrial Ethernet Switch is a critical component of any PLC network.

By providing:

• Reliable communication

• High bandwidth

• Redundancy

• Industrial-grade durability

these switches help maintain stable and efficient automation systems.

For most modern factories, a managed Gigabit industrial Ethernet switch with fiber uplinks, redundancy support, and industrial protection features offers the best long-term solution.

Investing in the right PLC networking infrastructure today helps ensure reliable operations and future scalability.

FAQ

Why are industrial switches used in PLC networks?

Industrial switches provide reliable communication, environmental protection, and advanced management features needed for industrial automation.

Is a managed switch necessary for PLC communication?

For simple machine networks, unmanaged switches may work. For larger or mission-critical systems, managed switches are strongly recommended.

What is the best network speed for PLC systems?

Gigabit Ethernet is generally recommended for new installations due to its scalability and future-proofing benefits.

Do PLC networks need fiber connections?

Large facilities often use fiber links between buildings or production areas to overcome distance limitations and improve reliability.