Modbus Lab

Modbus Lab is a fast, practical desktop Modbus master client built with Svelte 5 and Tauri v2.

This tool is powered by the modbus-rs stack, a modern Rust implementation designed for:

• embedded (no_std) systems
• deterministic behavior
• cross-platform use (desktop, RTOS, Baremetal, Linux)

This application serves as a real-world validation of the stack.

Designed for day-to-day Modbus operations, it features a highly responsive UI, rich polling controls, and detailed operation logs.

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🚀 Project Status: Alpha

The application is currently in alpha. It is fully usable for core Modbus TCP workflows, with active, ongoing development to expand protocol support and features.

Currently Implemented

• Connection Management: Modbus TCP UI with a protocol selector shell prepared for RTU/ASCII.
• Coils: Read (FC01), Single Write (FC05), Batch Write (FC15).
• Discrete Inputs: Read (FC02).
• Holding Registers: Read (FC03), Single Write (FC06), Batch Write (FC16).
• Input Registers: Read (FC04).
• Global Settings: Configurable poll defaults, display formats, layout forcing, and log preferences.
• App Logging: Dedicated log panel with filtering capabilities and native save-to-file export.

Planned Features (Placeholders)

• File Records (FC20/FC21)
• FIFO Queue (FC24)
• Diagnostics (FC08)

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📡 Protocol Support

Protocol	Status
Modbus TCP	✅ Implemented
Modbus RTU	✅ Implemented
Modbus ASCII	✅ Implemented

✨ Feature Summary

🔌 Connection

• Dedicated connection page featuring protocol cards and detailed TCP settings.
• Persistent connected/disconnected state badges in the global header.
• Device context chips displaying protocol, endpoint, and slave ID at a glance.

🟢 Coils & Discrete Inputs (FC01, FC02, FC05, FC15)

• Flexible Views: Toggle between dense table views and interactive switch-card views.
• Operations: Support for single read/write actions and pending batch writes for desired values.
• Polling: Granular polling controls with interval adjustments and limits.
• Addressing: Add custom address ranges or single custom addresses on the fly.

🔢 Registers (FC03, FC04, FC06, FC16)

• Flexible Views: Table and card views for both Input and Holding registers.
• Smart Editing: Compare "Read Value" versus "Desired Value" before committing writes.
• Advanced Filtering: Include/exclude specific addresses via ranges or lists.
• Intelligent Polling: Practical interval handling with chunked section planning for Input Registers.

📝 Logging & Settings

• Live Traffic Logs: Filter by ALL, INFO, WARN, and ERROR.
• Plan Logs: Scheduling and plan logs for grouped read/write operations.
• Native Export: Save logs directly to your local filesystem via a native desktop dialog.
• Customization: Tailor the experience with display formats (Decimal/Hex), log time precision, forced UI layouts (Auto/Vertical/Horizontal), and per-feature default limits.

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📸 Demo Screenshots

Connection

Coils

Discrete Inputs

Holding Registers

Input Registers

Log Examples

This helps debugging real-world Modbus communication issues.

INFO  Modbus Lab shell initialized.
INFO  [CONNECTION] connect.tcp start host=192.168.55.200 port=502
INFO  [CONNECTION] connect.tcp ok | status=connectedTcp (TCP 192.168.55.200:502)
INFO  fc01.read plan total=16 sections=1 ops=1 sample=[0..15]
INFO  fc01.read ok total=16 ok=16 sections=1
INFO  fc03.read plan total=16 sections=1 ops=1 chunkMax=125 sample=[0..15]
INFO  fc03.read ok total=16 ok=16 sections=1
ERROR fc04.read err addr=15 msg=Read input registers failed.

🛠 Tech Stack

This project bridges a cutting-edge web frontend with a high-performance native backend:

• Modbus Engine: modbus-rs (Custom Rust implementation)
• Desktop Runtime: Tauri v2
• Frontend: Svelte 5 + TypeScript + Vite
• Tooling: Tauri icon/bundle pipeline

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🎯 Who is this for?

• Industrial automation engineers
• Embedded developers working with Modbus devices
• PLC / SCADA developers
• Anyone testing or debugging Modbus TCP devices

📦 Installation

Download

Download the latest release from: 👉 https://github.com/Raghava-Ch/modbus-lab/releases

It is recommended to build from source yourself. See the Local Development section below for instructions.

Run

• Launch the application
• Enter Modbus TCP host and port
• Start reading/writing registers

⚡ Quick Start

1. Open the app
2. Navigate to the Connection page
3. Enter:
   • Host: 192.168.x.x
   • Port: 502
4. Connect
5. Go to Holding Registers
6. Read address range (e.g., 0–10)

💻 Local Development

Prerequisites

• Node.js 20+
• Rust toolchain + Cargo
• Tauri v2 Prerequisites for your specific OS (Windows, macOS, or Linux).

### Run web dev server
```bash
npm run dev

⚠ Limitations

• Advanced functions (file record, FIFO) are placeholders, planned for future releases.

Note: This tool is intended as both a daily-use Modbus client and a reference implementation for modbus-rs.

Run desktop app (Tauri)

npm run tauri dev

Type check

npm run check

Production build

npm run tauri build

📄 License

This project is dual-licensed:

• Will always be GPL v3 for open-source use

For contributing, see the Contributing guidelines.

Contact

Name: Raghava Ch
Email: ch.raghava44@gmail.com