modbus-webui v0.3.1

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

About

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

Source:  GitHub: modbus-webui

Lost your library from before 26.9.2025?

The domain changed as of 26.9.2025, so if you had a library saved on the old domain it will not be directly available from this page. You can import it by:

  1. Open Import/Export
  2. Click Import localStorage from old domain
  3. Follow popup and click Send to new site

  4. We apologize for the inconvenience.

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.

We’ll expand this section with examples and tips.

Name Tables

  • 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.
  • Versioned: Stored data has a version number so future updates can migrate it safely.
  • Import/Export: Planned; advanced users can manage the stored library manually for now.

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.