ESP8266 Scada SVG Modbus RTU Slave Serial - PDAControl
Modbus RTU - ESP8266 - Programming Questions - Arduino Forum
GitHub - birdtechstep/modbus-esp: A library that allows your ESP8266/ESP32 to communicate via Modbus protocol, acting as a master, slave or both. Supports IP via wireless network (Modbus IP) and RTU via Serial
ESP32 with MODBUS RTU RS485 Protocol Using Arduino IDE - microdigisoft.com