ESP-Modbus
The Espressif ESP-Modbus Library (esp-modbus) supports Modbus communication in the networks based on RS485, Wi-Fi, and Ethernet interfaces.
Since ESP-IDF version v5.0, the component freemodbus
has been moved from ESP-IDF to a separate repository:
Hosted Documentation
The documentation can be found through the link below:
Application Examples
The examples below demonstrate the ESP-Modbus library of serial and TCP ports for both slave and master implementations respectively.
protocols/modbus/serial/mb_slave demonstrates how to use ESP32 as a Modbus serial slave device with the esp-modbus stack, enabling an external Modbus host to read and write device parameters using the Modbus protocol.
protocols/modbus/serial/mb_master demonstrates how to use the esp-modbus stack port on ESP32 as a Modbus serial master device, capable of reading and writing values from slave devices in a Modbus segment.
protocols/modbus/tcp/mb_tcp_slave demonstrates the esp-modbus TCP slave stack port, allowing an external Modbus host to read and write device parameters via the Modbus protocol.
protocols/modbus/tcp/mb_tcp_master demonstrates how to use the esp-modbus stack port on ESP32 as a Modbus TCP master device, capable of reading and writing values from slave devices in a Modbus network.
Please refer to the README.md
documents of each specific example for details.
Protocol References
For the detailed protocol specifications, see The Modbus Organization.