Pull a cable in a star-topology EtherNet/IP network and one device goes dark. Pull a cable in a properly designed DLR ring and the network recovers in less than 3 milliseconds — fast enough that the PLC scan does not even register the change. That recovery time is the whole reason DLR exists. Engineers building motion-control machines, robotic… Read More »
HSR operates entirely at Layer 2. It doesn’t add a new protocol on top of Ethernet — it inserts a six-byte tag into every frame before it enters the ring. That tag is how nodes identify duplicates, track which path a frame took, and know when to remove a frame from the ring. Understanding the tag structure is… Read More »
very DANH on an HSR ring operates in one of six defined modes. They control how the node handles frame forwarding, tagging, and traffic removal. One is mandatory. The rest are optional. If you’re commissioning, testing, or troubleshooting an HSR network, knowing what each mode does — and what it breaks when misapplied — matters. The Short Version… Read More »
Zero-recovery-time redundancy is one thing. Getting your clocks right across that redundant network is another. In substation automation and industrial control, time synchronization isn’t optional — protection functions, event logging, and sampled value streams all depend on it. This article explains how PTP works specifically in PRP and HSR environments, what the standard requires, and where the practical… Read More »
HSR gives you zero recovery time. That part is guaranteed by the protocol. What’s not guaranteed — and what the standard deliberately leaves to implementation — is how much latency each node adds to the ring. That accumulates. Get the ring sizing wrong and you can end up with end-to-end delays that cause problems for time-sensitive applications, even… Read More »
PRP and HSR both deliver zero-recovery-time redundancy — but they work differently, and mixing them takes more than just plugging cables together. This guide walks through every connection scenario defined in IEC 62439-3, what device you need for each one, and what to watch out for when you’re laying out the topology. Before You Start: Know What You’re… Read More »
If you’re working with PRP or HSR networks, you’ll run into the RedBox and QuadBox. They solve two different problems: the RedBox gets non-redundant devices onto a redundant network; the QuadBox ties two HSR rings together. This article breaks down how each one works, what the standard actually specifies, and where the two are commonly confused. RedBox: The… Read More »
High availability is a mandatory requirement in modern industrial automation networks. Process control, power systems, water treatment plants, and safety-critical infrastructures cannot tolerate long communication interruptions. Beacon Redundancy Protocol (BRP) is an Ethernet-based redundancy protocol standardized in IEC 62439-5. It provides deterministic fault detection and fast recovery against single point failures while keeping the network architecture simple and… Read More »
Industrial communication networks are very different from office or IT networks. In factories, substations, water plants, and process industries, communication is part of the control system itself. If data stops flowing, machines can stop, processes can become unstable, alarms may be delayed, and safety can be affected. Because of this, industrial networks must be highly available, predictable, and… Read More »
Industrial Ethernet networks form the backbone of modern SCADA, substation automation, manufacturing, and process control systems. Unlike traditional office IT networks, industrial networks must provide high availability, predictable behavior, and fast recovery from failures. Even short communication interruptions can lead to production losses, control instability, or safety risks. To meet these requirements, redundancy is commonly built into industrial… Read More »