GitHub - ethicstechOSS/Modbus-Slave: A library that allows your Arduino or MSP to communicate via Modbus protocol, acting as a slave. Supports serial (RS-232, RS-485), LoRa RN-2483 and IP via Ethernet (Modbus IP).
Modbus with C#: libraries, code, utilities and examples – Mesta Automation
FieldTalk Modbus Master C++ Library / RTOS Edition
✓ How to use Modbus TCP Slave library with a PLC controller Arduinosearch