A browser-based Modbus RTU master using the Web Serial API. Supports FC01–FC06, FC15, FC16 with device profiles, per-register data type interpretation, minus offset addressing, and raw frame inspection.
Fonts: JetBrains Mono & Outfit — SIL Open Font License 1.1 Technology: Web Serial API (Chrome/Edge 89+) No external libraries or frameworks.
This is free and unencumbered software released into the public domain.
Anyone is free to copy, modify, publish, use, compile, sell, or distribute this software, either in source code form or as a compiled binary, for any purpose, commercial or non-commercial, and by any means.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
For more information, please refer to <https://unlicense.org>
Device Profile Editor
Define labels and data types for coils, inputs, and registers. Save profiles locally or export/import as JSON files to share between sessions.
TypeAddressLabelData Type
Saved Profiles
MB
Modbus RTU Master / Serial Client
✕
Disconnected
Serial Port Configuration
Slave Configuration
Minus Offset
Subtracts from start address before sending on wire. e.g. Start 10001, Offset 10001 → Wire 0
Auto-Polling
Automatically re-sends the current query at the specified interval.