Per Alicat, Modbus RTU was added as standard in 2018/2019. [ModbusRTU_Manual_Legacy-1.pdf](https://github.com/user-attachments/files/23032449/ModbusRTU_Manual_Legacy-1.pdf) [DOC-MANUAL-MODBUS-1.pdf](https://github.com/user-attachments/files/23032450/DOC-MANUAL-MODBUS-1.pdf)
