Modbus Master
Communicate using RTU, TCP/IP and RTU over TCP/IP.
Free Modbus Toolkit for Windows and Linux
The Swiss Army Knife for Modbus Networks
Analyze, simulate, monitor and troubleshoot Modbus networks with a complete collection of engineering tools in one portable application.
Latest
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Completely Free No
Ads No Installation Portable
Modbus RTU
Serial communication
Modbus TCP/IP
Ethernet communication
RTU over TCP/IP
Serial frames over TCP
Windows + Linux
Portable 64-bit application
Complete
toolkit
One application. Multiple professional Modbus tools.
Built for commissioning, diagnostics, troubleshooting, reverse engineering, protocol learning and embedded firmware development.
RTU Sniffer
Passively monitor communication on existing Modbus RTU networks.
Slave Simulator
Simulate Modbus devices, memory and exception responses.
Device Scanners
Discover devices, serial settings, addresses and TCP endpoints.
Traffic Analyzer
Inspect communication activity, valid frames and errors in real time.
Time Graph
Plot register values over time and monitor dynamic processes.
CRC Validation
Validate RTU frames and quickly identify corrupted messages.
Activity Logging
Record communication sessions for troubleshooting and analysis.
Multiple Data Formats
Work with multiple numeric formats and universal register tables.
Engineering tools
Built for real-world Modbus diagnostics.
Go beyond basic register reading with dedicated tools for discovering, analyzing and troubleshooting industrial devices.
01 — ANALYZE
Traffic Data Analyzer
View Modbus communication in real time and isolate intermittent communication problems without digging through raw logs manually.
- Valid frame and error filtering
- Real-time communication diagnostics
- Search and data highlighting
- CSV data export
02 — DISCOVER
Device Scanner
Discover Modbus devices and explore supported functions and accessible register areas automatically.
- Device ID scanning
- Function Code discovery
- Register Address scanning
- Exception response detection
03 — IDENTIFY
Serial RTU Scanner
Connect to an unknown Modbus RTU device and automatically search for the serial parameters required for communication.
- Baud Rate scanning
- Parity and Stop Bits discovery
- Slave ID scanning
- CRC response validation
04 — FIND
TCP/IP Scanner
Search the local network for Modbus TCP devices when the target IP address or communication port is unknown.
- IP address scanning
- TCP port scanning
- Device ID detection
- Modbus response validation
05 — VISUALIZE
Time Graph
Plot Modbus register values over time to visualize trends, oscillations and dynamic system behavior.
- Up to 8 independent traces
- Automatic or manual scaling
- Multiplication factor and offset
- Configurable time scale
06 — REVERSE
ENGINEER
Wide Vision
Monitor large memory areas and quickly identify which registers change while interacting with a device.
- Large register area monitoring
- Automatic change detection
- Visual register highlighting
- Ideal for reverse engineering
07 — MONITOR
Integrated Modbus RTU Sniffer
Passively monitor communication between an existing Modbus Master and one or more Slave devices.
- Real-time frame monitoring
- Master and Slave identification
- CRC validation
- Communication diagnostics
08 — SIMULATE
Internal Slave Simulator
Emulate Modbus Slave devices directly inside ScanBus-BR for PLC, software and embedded firmware development.
- Editable Slave memory
- Standard Modbus functions
- Exception response simulation
- Communication error simulation
Designed
for the field
From development bench to industrial maintenance.
Industrial Automation
Test and diagnose communication with PLCs and industrial equipment.
PLC Commissioning
Validate registers, communication parameters and device responses.
Embedded Development
Develop and validate Modbus firmware without additional test equipment.
Industrial Maintenance
Find intermittent communication faults and unknown device configurations.
Reverse Engineering
Discover registers and observe device behavior without documentation.
Technical Support
Reproduce communication problems and analyze protocol behavior.
Protocol Learning
Explore Modbus frames, functions, exceptions and communication flow.
Educational Use
Learn and demonstrate Modbus communication using practical tools.
Portable
application
Run it. Connect. Start working.
No installer and no complicated setup. Extract the package and start using ScanBus-BR.
Windows
Compatible with Windows 7, Windows 10 and Windows 11 — 64-bit.
Linux
64-bit Linux support with compatibility across most distributions.
Available languages: English · Português · Español · Italiano
Community
Questions, ideas or feedback?
Join the ScanBus-BR community, report issues, discuss Modbus and help improve the project.
Support
the Project
Help keep ScanBus-BR free for everyone.
ScanBus-BR is an independent project developed and maintained during my free time. The software is completely free, with no advertisements, subscriptions, paid versions or hidden features.
Donate via PayPal
Support the development of ScanBus-BR with a secure donation through PayPal.
Donate with PayPalDonate via PIX
For users in Brazil, you can support the project directly using PIX.
If ScanBus-BR has helped you solve a
problem or saved valuable development time, consider supporting the
project. Every contribution helps fund future improvements and new
features.
Thank you for helping keep ScanBus-BR free for everyone. ❤️
Get ScanBus-BR
A complete Modbus toolkit. Completely free.
Freeware. No advertisements. No bundled software. No installation required. Download the latest portable release for Windows or Linux.
Downloads are distributed through the official GitHub Releases page.