Blog
Insights on OPC UA, industrial connectivity, and open-source engineering from the creators of node-opcua.
Connecting Siemens S7 and Modbus PLCs to OPC UA β the brownfield guide
Most plants don't need new PLCs β they need their existing S7 and Modbus devices to speak OPC UA. Here's how brownfield-to-OPC-UA actually works, where hand-rolled gateways go wrong, and how to do it with one YAML file.
Read articleThe Missing Safety Layer β and How to Bridge It (Part 3/3)
i3X has no alarms, no method calls, no event subscriptions, and no support for dynamic address spaces. In regulated industries, this is a compliance blocker. Here's what's missing, why it matters, and how Sterfive's node-i3x bridges the gap.
Read articleOne API Call to Rule Them All β and Its Limits (Part 2/3)
i3X treats every OPC UA object as a decomposable asset β one REST call returns the entire machine state. But this elegant model has cracks: missed transitions, lost counts, and no deadband control. Here's why.
Read articlei3X Meets OPC UA: When REST Meets Real-Time (Part 1/3)
i3X and OPC UA share the same information-modeling DNA β typed hierarchies, namespaces, and VQT data atoms. This article explores why they are complementary layers, not competitors, and introduces Sterfive's node-i3x bridge.
Read articlei3X and OPC UA β a practical introduction
i3X is the new REST API standard from CESMII that makes OPC UA data accessible to IT developers. This 101 guide explains what i3X is, how it relates to OPC UA, and where each fits in your architecture.
Read articleOPC UA in one-way networks β the Data Diode approach
OPC UA is bidirectional by design. But some environments demand strictly one-way data flow. This article explains the Data Diode pattern β how to replicate OPC UA data across security boundaries without opening a return channel.
Read articleWhat is an OPC UA GDS? Certificate management explained
The Global Discovery Server (GDS) is the PKI backbone of OPC UA. This guide explains what it does, why you need one, and how it simplifies certificate management across your OPC UA deployment.
Read articleBuilding a fully compliant OPC UA server β from Companion Spec to brownfield
How to build an OPC UA server that implements Companion Specifications, exposes a rich information model, and connects to legacy PLCs and brownfield equipment β all through configuration, not code.
Read articleThe future of industry starts with semantic modeling
Before AI can transform manufacturing, machines need a common language. OPC UA Companion Specifications provide exactly that β and they are the missing foundation that separates industrial AI pilots from production-grade systems.
Read articleOPC UA vs MQTT β when to use what in industrial IoT
OPC UA and MQTT solve different problems. This guide breaks down when to use each β and when to use both β with concrete architecture patterns for OT/IT convergence.
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