Commercial library by Step Function I/O

rodbus

Rust async/await implementation of the Modbus protocol using Tokio with idiomatic bindings for C/C++, Java, and .NET Core.

License

Refer to License.txt for the terms of the non-commercial license. This software is "source available", but is not "open source". You must purchase a commercial license to use this software for profit.

Library

The client and server examples demonstrate simple usage of the API.

The following function codes are supported:

• Read Coils (0x01)
• Read Discrete Inputs (0x02)
• Read Holding Registers (0x03)
• Read Input Registers (0x04)
• Write Single Coil (0x05)
• Write Single Register (0x06)
• Write Multiple Coils (0x0F)
• Write Multiple Registers (0x10)

The library uses the Tokio executor under the hood. The perf example is a benchmark that creates multiple sessions on a single server and sends multiple requests in parallel. On a decent workstation, the benchmark achieved around 200k requests per second spread across 100 concurrent sessions in only 800 KB of memory.

Future support

• Modbus Security using TLS
• Modbus RTU (serial)

Bindings

Bindings in C, .NET Core and Java are available for this library. See the documentation for more details.

Modbus client CLI

You can test Modbus servers from the command line with the rodbus-client crate.