🐍 ModbusSniffer – Free Modbus RTU Analyzer with GUI (Python / PyQt6)

A lightweight and user-friendly Modbus RTU sniffer tool with a graphical interface.  
Easily analyze and debug communication between PLCs, HMIs, and other Modbus RTU devices via serial ports.

🔧 Features

- 🧰 Sniffs raw Modbus RTU frames from serial ports (RS-485, USB)
- 🖥️ GUI interface built with PyQt6
- 📋 Frame table: Real-time decoded Modbus traffic
- 🌈 Color-coded logging of request–response frames
- 🪟 Cross-platform: Windows & Linux
- 🆓 MIT licensed, open-source

📦 Installation

Install directly from PyPI:

pip install modbus-sniffer

 

or download Binary files for Ubuntu and Windows from here

You can also build and install app from sources. Click here for details about it.

▶️ Usage

🎛️ Run GUI:

modbus-sniffer-gui

🖥️ Run CLI:
To list all options:

modbus-sniffer -h

Example of runnig sniffer on ttyUSB0 with baud 115200 and no parity:

modbus-sniffer -p /dev/ttyUSB0 -b 115200 -r none

For more usage options, development guide, and installation from source, visit the GitHub repository or app web page:

👉 Modbus Sniffer on GitHub

👉 ModbusSniffer app web page

🤝 Contributing

Please see CONTRIBUTING for development setup and contribution guidelines.

📜 License

MIT License — see the LICENSE file for details.  
This project is a fork of BADAndrea ModbusSniffer CLI, maintained by niwciu, with enhancements described above.