// the find
rossmann-engineering/EasyModbusTCP.NET
Modbus TCP, Modbus UDP and Modbus RTU client/server library for .NET implementations
A Modbus TCP, UDP, and RTU client/server library for .NET, covering all three transports in a single package. Targets everything from .NET 4.0 to .NET 6, making it useful for legacy industrial systems as much as modern ones. Squarely aimed at developers who need to talk to PLCs without writing Modbus framing from scratch.
- Covers all three Modbus transports (TCP, UDP, RTU) in one library — most alternatives pick one or two, forcing you to juggle packages when a project has mixed hardware.
- Ships both client and server implementations, plus a standalone server simulator. For dev work without physical PLC hardware, having a simulator in the same repo is genuinely useful.
- Function code coverage is complete for practical use: FC1–FC6, FC15, FC16, FC23 covers 95% of real-world Modbus deployments.
- 446 forks in a niche this narrow is a real signal — industrial automation teams have actually used and adapted this, which matters more than star counts for infrastructure-level libraries.
- The multi-version story is a mess: separate project folders for Net40, NET5, and Net60 instead of a proper multi-targeted csproj. You get code drift between versions and no guarantee they behave identically.
- No visible test suite anywhere in the tree. For a protocol implementation where off-by-one errors in byte framing break real hardware, the absence of tests is a serious problem.
- The API appears to be synchronous throughout. Modbus polling loops in production almost always need async — without it, you're blocking threads or wrapping everything in Task.Run yourself.
- Last meaningful activity is mid-2024, copyright reads 2018–2020, and the NET5 folder still exists as a separate project rather than being merged. The library feels effectively finished, which is fine until a .NET version ships something that breaks it.