Category Archives: Communication Protocols

PROFINET GSD/GSDML Files Explained: What They Are and How to Use Them

Every PROFINET device comes with a GSD file. Without it, your PLC does not know the device exists. It cannot configure modules, exchange I/O data, or read diagnostics. GSD stands for General Station Description. In PROFINET, GSD files are written in XML format. The language used is called GSDML — General Station Description Markup Language. The file extension… Read More: PROFINET GSD/GSDML Files Explained: What They Are and How to… »

IEC 61850 Logical Nodes Explained: Complete Reference for Substation Engineers

Every piece of data in an IEC 61850 system lives inside a logical node. A circuit breaker position is inside XCBR. An overcurrent trip signal is inside PTOC. A voltage measurement is inside MMXU. A GOOSE control block is inside LLN0. Logical nodes are the building blocks of the IEC 61850 data model. They represent functions — not… Read More: IEC 61850 Logical Nodes Explained: Complete Reference for Substation Engineers »

Modbus Register Map Explained: How to Read Any Device’s Register Map

Every Modbus device comes with a register map. It is usually a table in the user manual or a separate PDF that lists all the data points the device makes available — voltages, currents, setpoints, alarms, status bits, and configuration parameters. Reading a register map sounds simple. But it is one of the most common sources of errors… Read More: Modbus Register Map Explained: How to Read Any Device’s Register… »

OPC UA vs OPC DA: The Full Comparison Every Engineer Needs

OPC DA was the workhorse of industrial communication for over two decades. It connected PLCs to SCADA systems, HMIs to historians, and control rooms to the factory floor. It worked. But the world changed. Linux grew. Cloud computing arrived. Cybersecurity became critical. And OPC DA — locked to Windows, with no encryption, dependent on a technology Microsoft has… Read More: OPC UA vs OPC DA: The Full Comparison Every Engineer… »

OPC UA Pub/Sub: Complete Technical Guide for Engineers

OPC UA Pub/Sub is a communication pattern within the OPC UA standard that allows data to flow from publishers to subscribers without requiring a direct connection between them. A publisher sends data to a message broker or network bus. Any number of subscribers receive that data independently. No handshake. No dedicated session. No request-response cycle. This is fundamentally… Read More: OPC UA Pub/Sub: Complete Technical Guide for Engineers »

IEC 61850 SCL File Types Explained: ICD, SSD, SCD, IID, CID, and SED

If you work with IEC 61850, you will deal with SCL files. They are the standard way to describe IED capabilities, substation configurations, and communication parameters. But the first thing that confuses most engineers is this: there are six different SCL file types. ICD, SSD, SCD, IID, CID, SED — each with a different purpose, created by a… Read More: IEC 61850 SCL File Types Explained: ICD, SSD, SCD, IID,… »

How to Set Up IEC 60870-5-104 for SCADA Remote Monitoring

IEC 60870-5-104 (commonly called IEC 104) is the standard protocol for SCADA communication in power utilities, water systems, and other critical infrastructure across Europe, Asia, and the Middle East. It takes the application layer of IEC 60870-5-101 (the serial telecontrol standard) and maps it onto TCP/IP. This gives you the same proven data model — single-point indications, measured… Read More: How to Set Up IEC 60870-5-104 for SCADA Remote Monitoring »

IEC 61850 Security: Threats, IEC 62351, and How to Protect Your Substation

IEC 61850 transformed substation automation. It replaced hardwired copper connections with standardized Ethernet-based communication between intelligent electronic devices (IEDs). GOOSE messages trip breakers in under 4 milliseconds. MMS connects IEDs to SCADA systems. Sampled Values stream real-time voltage and current measurements. But this transformation came with a trade-off. By moving protection and control communications onto Ethernet, substations inherited… Read More: IEC 61850 Security: Threats, IEC 62351, and How to Protect… »

Modbus Security Risks and How to Protect Your Industrial Network

Modbus was built in 1979 for a world where industrial networks were physically isolated. There was no internet, no remote access, and no reason to worry about authentication or encryption. The protocol was designed for reliability and simplicity — not security. That was fine for decades. But today, industrial control systems are increasingly connected to corporate networks, cloud… Read More: Modbus Security Risks and How to Protect Your Industrial Network »