modbus-webui v0.4.0

Single-file Modbus workbench—profiles, name tables, shortcuts, fully offline-capable.

About

Runs entirely in your browser; powered by the Web Serial API using modbus-webserial.

Privacy: No analytics or tracking scripts are loaded.

Offline: Download this single HTML file and run it locally or inside air-gapped networks.

Download modbus-webui.html for offline use (or use GitHub Releases if your browser blocks direct download)

Source:  GitHub: modbus-webui

Custom implementations or feature requests:  antti.kotajarvi@hotmail.com

Help / Basic usage

  1. Click Connect and choose your serial port.
  2. Set port parameters (baud rate, parity, etc.) and click Open.
  3. Use the Read and Write panels to work with coils and registers.
  4. Save frequent actions as Shortcuts and run them from the Shortcuts panel.
  5. Use Name Tables to label addresses; Profiles keep your device-specific setup.

Tip: You can bookmark this page or save the HTML file for local/offline reuse.

Nametables

  • Shared library: Name tables are global; any profile can choose which set to use.
  • Covers all areas: Coils, discrete inputs, holding registers, and input registers.
  • Address-based: Each name is linked to an address (you can enter addresses as decimal or hex). Gaps are fine.
  • Edit easily: Open the Name Tables modal to edit one area or copy/paste an entire set in JSON.

Profiles

  • What they hold: Your selected name-table set, connection settings, and saved write shortcuts.
  • Live changes: Edits apply to the active profile immediately—no separate “save profile” step.
  • Switching: Changing profiles doesn’t close the serial connection; disconnect explicitly if needed.
  • Names: Tag-style identifiers (capitals/underscores). The input field enforces the format.

Storage & Versioning

  • Your library: All data (name tables, profiles, the active profile) is kept together as a single “library”.
  • Persistence: The library is saved in your browser storage automatically or when you choose to save.
  • Migration-proof storage: Library data uses strong versioned migrations so older storage files remain migration-proof across updates.
  • Import/Export: You can manage your storage by importing/exporting your library as a JSON file.

Browser support

  • Requires Web Serial: Works on Chromium-based desktop browsers. A notice appears if it isn’t available.
  • Permissions: You choose a port each session; after a page reload you may need to pick it again.