QModMaster
QModMaster (open-source project)
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sourceforge.net
A graphical program for talking to Modbus devices over RTU (serial) and TCP. It acts as the master: it reads and writes registers and coils on PLCs, energy meters, variable-frequency drives and sensors, and a built-in monitor shows the traffic on the line. It is a common tool for commissioning, testing and troubleshooting automation and building-control systems, and it is updated regularly.
Ratings & Reviews
| Licence type | Completely Free, Open Source |
|---|---|
| Licence terms | Open-source licence (LGPLv3). Free for any purpose including commercial work, with no time limit, no registration and no licence key. |
| Platforms | Linux, Windows |
| Engineering field | Electrical & Electronics |
| Tool type | Engineering Calculators |
| Vendor site | qmodmaster.sourceforge.io |
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Last verified: 2026-09-30
