Every modern industrial automation system requires a level of networking configuration. In today’s industrial applications, networks function as the backbone of connecting PLCs, HMIs, drives, sensors, and enterprise softwares. Understanding industrial networking principles helps engineers design more reliable systems, troubleshoot communication issues, and prepare equipment for future expansion.
Common Industrial Networking Terms Every Engineer Should Know
- IP Address: IP addresses function as the device’s primary identifying feature on any network. Assigning a unique numerical address to each device will allow for cross-network communication.
- Switch: Switches connect devices within your local network. Functioning as a meeting point for device traffic, before departing towards their destination.
- Router: Routers function by connecting different networks together; routers typically function at the outermost layer before traffic departs the network.
- Protocol (Ethernet/IP, Modbus): Protocols are a set of rules that devices will follow to communicate in a coordinated manner for specific environments.
- Latency: The delay that happens during communication when devices are exchanging information, the shorter latency, the better.
- Bandwidth: Tells us how much data can move at one point in time. The more bandwidth, the more data the network can transmit simultaneously.
- Topology: The overall scheme in which devices are connected. Some common topologies include ring, star, point-to-point, and bus.
How Industrial Communication Networks Work
Since we now know some common networking terms, we can properly introduce a very simple explanation of how devices may communicate across a network. A device sends its data in what are called packets, which are essentially digital envelopes containing information in pieces. A switch moves packets within the network, sending each to the recipient with the specified IP address. A common protocol ensures that each device understands how to read the messages it receives.
Why Industrial Networking Matters in Automation
Networking can be directly tied to real-time control of equipment, the monitoring of processes, and the coordination of multiple machines. For example, when a PLC sends a command to a motor controller, it’s crucial that the message the controller receives is delivered reliably and quickly. Small disruptions in the communication process can snowball into a major issue with production.
Connecting Legacy Equipment to Modern Industrial Networks
Not long ago, industrial equipment largely ran on a single dominant standard: serial communication. This technology used cable-based protocols to transmit data along a bus or trunk line, with some devices supporting only point-to-point connections and others enabling one-to-many configurations. While serial communication still has a presence in many facilities today, it’s rapidly being overtaken by faster, more capable alternatives including Ethernet, Single-Pair Ethernet (SPE), EtherCAT, and a growing range of proprietary vendor solutions, each promising to reshape how industrial systems connect and communicate.
To bridge the gap, many vendors now offer gateway integration devices that extract data from legacy systems while preserving their existing communication interfaces, allowing older equipment to coexist alongside modern infrastructure without requiring a full replacement.
Troubleshooting Network Issues
We can’t have a proper introduction to networking without discussing situations in which the network or more specifically, devices on the network don’t function as expected. While network issues have a plethora of causes, there are a few things to look out for:
- Incorrect network configuration: The IP address being the unique identifier must be, well, unique. It should also be on the same IP subnet (e.g., reachable) from any other device that it must communicate with.
- Security constraints: Whether a blocked port, application, or IP, these are all scenarios in which IT experts at the facility must intervene to unblock or whitelist connections on the network.
- Assumptions on topology: Due to complex subnetting or routing rules it may not always be clear if you can reach a specific device or service on the network.
So, what is the easiest way to troubleshoot a suspected networking issue?
For non-experts, this is arguably by the use of simple network commands and via process of elimination. While not practical in every situation, eliminating points of failure will help you narrow down the root cause of any issue. As an example, how can you find out if a networking device is acting as a bottleneck thereby introducing latency or otherwise preventing communication? Simply try to ping the device or perform a tracert. Then, establish a direct connection to the target device.
This removes network traffic middlemen like routers or switches from the equation. After which, if you can reach the device, it is likely that the issue is related to the “middlemen” equipment. If not, it may be due to network configuration on the target device or an issue with its hardware.
Industrial Networking Best Practices
Here are some practices we recommend when implementing and maintaining your industrial networks:
- Network segmentation: Separate your control systems from the business network, this will reduce the likelihood of a large scale outage and reduce congestion.
- Monitor performance: Implement ways to observe packet loss, latency, and other unwanted conditions, to ensure your network is functioning without any roadblocks.
- Document the topology: Know what is connected and where it is located. Understanding the topology is crucial for resolving issues during troubleshooting
- Ensure scalability: Everything implemented currently will grow over time, building a network with room and organization to implement more devices in the future will save money and time.
- Use equipment that can handle the job: Use networking hardware (including cables) that can withstand the environmental conditions of your application. This includes planning for ambient temperature, humidity, vibrations, electronic noise, etc. This will reduce the likelihood of downtime due to damaged equipment.
Whether you’re connecting a new production line or modernizing legacy equipment, understanding industrial networking is the foundation for reliable automation. While networks become more connected, it is also true that they can become more exposed. In a later article, we’ll explore how to secure those networks against today’s growing cybersecurity threats.
Key Takeaways:
- Supporting multiple protocols is essential for meeting strict application needs.
- The protocol chosen should always reflect the structure, processing speed, and feature requirements of the application.