300+ SCADA Protocol Articles & Guides
Deep dives on Modbus, DNP3, IEC 60870-5-101/104, IEC 61850, OPC UA, Profinet, MQTT, IEC 62443, and substation automation — written for practicing engineers.
Modbus to MQTT: How the Gateway Bridge Works
Modbus to MQTT explained: how a gateway maps registers to topics, builds JSON payloads, and handles reads, writes, QoS and TLS. With a worked example.
Modbus Parity and Character Format
Modbus parity and character format: data bits, parity, and stop bits for RTU and ASCII, the even-parity default, the two-stop-bit rule, and what parity misses.
Modbus Unit Identifier Explained: Unit ID by Scenario
Modbus Unit Identifier (Unit ID) explained by scenario: direct TCP devices, RTU gateways, multi-port gateways. Value ranges, common defaults, troubleshooting.
Modbus Broadcast Function Codes: Address 0 Explained
Modbus broadcast on address 0: which function codes support it, how serial and TCP differ, turnaround timing, gateway behavior, and when to actually use it.
Modbus Client-Server vs Master-Slave Terminology
Modbus client-server vs master-slave: the 2020 terminology change explained. What stays the same, translation table, and how to read mixed-terminology docs.
Modbus TCP MBAP Header Explained: 7 Bytes Byte by Byte
Modbus TCP MBAP header decoded byte by byte: Transaction ID, Protocol ID, Length, and Unit ID, with a real hex dump, network byte order, and common mistakes.
Modbus TCP Security Explained: TLS on Port 802
Modbus TCP Security explained: TLS on port 802, X.509 certificates, role-based access control, deployment alongside port 502, cipher suites, real setup.
Modbus Byte Order and Word Order: Fix Your 32-Bit Values
Modbus byte order and word order decoded: ABCD, CDAB, BADC, and DCBA. Fix reversed floats and byte-swapped longs, with a five-minute test and vendor defaults.
Modbus Exception Codes Explained: Complete Reference
Modbus exception codes 01 through 0B in full: Illegal Function, Illegal Data Address, Slave Device Failure, and gateway errors, each with the fix that works.
Top 10 Free Modbus Simulators
Top 10 free Modbus simulators for RTU and TCP testing — slave and master tools with setup steps, command-line examples, and download links.
Modbus Poll Android App: Read, Write, and Test Modbus Devices From Your Phone
Turn your Android phone into a Modbus master. Connect over Wi-Fi, read registers, write coils, and debug PLCs on-site - no laptop needed.
Modbus Register Map Explained: How to Read Any Device
Modbus register map reading made reliable: the four register types, the zero-based offset trap, data types inside registers, byte order, and scale factors.
SCADA Protocol Analyzer: Decode Industrial Protocols on Your Phone
Decode DNP3, Modbus TCP/RTU, IEC-104, and IEC-101 hex frames on your Android phone. Paste, decode, and analyze SCADA protocol traffic anywhere - no laptop needed.
Modbus Function Codes Explained with Real Examples
Modbus function codes with real hex frames: FC 01 to 06, FC 15 and 16, FC 23 and 43, plus register type matching and the mistakes that cause exceptions.
Modbus Security Risks and How to Protect Your Network
Modbus security risks in practice: why the protocol has no authentication, real attack techniques on RTU and TCP, plus segmentation, firewalls, and monitoring.
How to Configure Modbus RTU Over RS-485: Step-by-Step
Modbus RTU over RS-485 configured step by step: bus wiring and topology, termination and biasing, addressing, register types, and T1.5 and T3.5 timing.
Modbus TCP/IP Setup: Step-by-Step Configuration Guide
Modbus TCP/IP setup from scratch: IP planning, server and client configuration, MBAP header basics, gateway bridging to RTU, and connection troubleshooting.
OPC UA vs MQTT vs Modbus: Which Protocol Should You Use?
OPC UA vs MQTT vs Modbus: Which protocol fits your project? Compare security, speed, data modeling, and scalability to pick the right one for your IIoT system.