Knowledge Base

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.

Showing 109126 of 280 articles
PLC Communication
MODBUS

Modbus TCP Schneider M340: Unity Pro Setup Guide

Modbus TCP Schneider M340 configuration: CPU embedded port, NOE 0100 and NOC 0401 modules, server and client roles, READ_VAR, WRITE_VAR, and ADDM explained.

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OPC UA Protocol
OPC-UA

OPC UA NodeId Explained: Namespace Index, Identifier Types, and Format

Complete guide to OPC UA NodeId. Covers namespace index, four identifier types (Numeric, String, GUID, Opaque), notation, well-known NodeIds, and best practices.

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Profinet Protocol
PROFINET

PROFINET Port Numbers Explained: UDP 34962/34963/34964, Ethertype 0x8892, and Firewall Configuration

Complete guide to PROFINET ports. Covers UDP 34962, 34963, 34964, 49152, Ethertype 0x8892 for cyclic I/O, MRP 0x88E3, firewall rules, and Wireshark filters.

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Modbus Protocol
MODBUS

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.

14
OPC UA Protocol
OPC-UA

OPC UA Port Number Explained: TCP 4840, Discovery, and Firewall Configuration

Complete guide to OPC UA port 4840. Covers IANA registration, endpoint URL format, Local Discovery Server, firewall rules, Wireshark filters, and security.

12
CIP Protocol
CIP

CIP Object Model Explained: Classes, Instances, Attributes, and Services

Understand the CIP object model used in EtherNet/IP, DeviceNet, and ControlNet. Covers classes, instances, attributes, services, Forward Open, and error codes.

19
IEC 60870-5-104 Protocol
IEC-104

IEC 60870-5-104 Type IDs Explained: Complete Reference Guide

Complete reference for all IEC 60870-5-104 type IDs. Covers monitor, control, system, parameter, and file transfer ASDUs with data formats, quality flags, and COT.

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Blog
MODBUS

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.

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Wireshark Tutorials
CIP

Wireshark EtherNet/IP: Decode CIP Traffic

Wireshark EtherNet/IP capture and decode: CIP services, Forward_Open on TCP 44818, implicit I/O on UDP 2222, status codes, and connection troubleshooting.

9
Wireshark Tutorials
MODBUS

Wireshark Modbus RTU: Decode Serial RS-485 Traffic

Wireshark Modbus RTU over RS-485: COM port setup with a serial adapter, DLT 147 configuration, display filters, and how to read framing and CRC errors.

12
Protocol Decoders
MODBUS

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.

6
PLC Communication
PROFINET

PROFINET TIA Portal Configuration: Step-by-Step Guide

PROFINET TIA Portal configuration step by step: GSD install, device naming, module setup, I/O address mapping, update time, download, and online diagnostics.

12
Profinet Protocol
PROFINET

PROFINET Conformance Classes Explained: CC-A, CC-B, CC-C (IRT), and CC-D (TSN)

Understand PROFINET conformance classes CC-A, CC-B, CC-C with IRT, and CC-D with TSN. Covers RT classes, cycle times, switch requirements, and which class to use.

12
Wireshark Tutorials
TLS

Decrypt Industrial Protocol Traffic in Wireshark

Decrypt industrial protocol traffic in Wireshark using SSLKEYLOGFILE: TLS-secured Modbus TCP on 802, IEC 104 on 19998, IEC 61850 MMS, and OPC UA sessions.

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PLC Communication
MODBUS

Modbus TCP CompactLogix Setup in Studio 5000

Modbus TCP CompactLogix setup with Rockwell's free AOI in Studio 5000: client and server roles, AOI parameters, polling multiple devices, and gateway options.

11
Profinet Protocol
PROFINET

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

Learn what PROFINET GSD and GSDML files are, how to read the XML structure, import into TIA Portal, troubleshoot problems, and find the latest files from vendors.

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Blog
PROFINET

PROFINET vs EtherNet/IP: Complete Comparison for Industrial Engineers

PROFINET vs EtherNet/IP compared: protocol architecture, real-time performance, GSDML vs EDS, PROFIsafe vs CIP Safety, installed base, and when to choose each.

11
Wireshark Tutorials
DNP3

Wireshark DNP3: Capture, Filter, Troubleshoot

Wireshark DNP3 analysis end to end: display filters, function codes, IIN bits, quality flags, CRC errors, and how to trace an unsolicited response.

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