Zakaria El Intissar

I've spent 13 years in power system automation, electrical protection, and SCADA communication, as an automation and industrial computing engineer. ScadaProtocols.com is where I turn what I've learned on site into plain guides and working tools — so other engineers can decode, analyze, and troubleshoot industrial communication protocols without the guesswork.

Author Archives: Zakaria El Intissar

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… »

OT Security: Complete Guide to Operational Technology Protection

OT security is the practice of protecting operational technology — the hardware and software that monitors and controls physical processes — from cyber threats. This includes the systems that run factories, power plants, water treatment facilities, oil refineries, transportation networks, and any environment where digital commands drive physical outcomes. Operational technology is different from information technology. IT manages… Read More: OT Security: Complete Guide to Operational Technology Protection »

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 »

SCADA Security: Complete Guide to Protecting Control Systems

SCADA security is the practice of protecting Supervisory Control and Data Acquisition systems from unauthorized access, tampering, and cyberattacks. SCADA systems monitor and control physical processes across large geographic areas — power grids, water pipelines, oil and gas networks, and transportation systems. These systems were never designed with cybersecurity in mind. They were built for reliability. For decades,… Read More: SCADA Security: Complete Guide to Protecting Control Systems »

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 »