Introduction↗
To facilitate the development and testing of a new Modbus acquisition module, we required a software-based simulator to avoid relying on physical hardware during the early stages.
After conducting a survey of existing solutions, two relevant projects were identified:
- NModbus 3.0.78 —
https://www.nuget.org/packages/NModbus - modbusPlcSimulator —
https://github.com/alongL/modbusPlcSimulator
Building on these findings, a dedicated playback‑oriented simulator was developed.
This command‑line utility is capable of emulating an arbitrary number of Modbus devices and reproducing deterministic data sequences sourced from CSV files.
The simplest way to use the simulator is through Modbus TCP. However when combined with an RS485 usb dongle, it can also emulate a Modbus RTU network.
The simulator is published as an open‑source project and is available in this GitHub repository.