Home automation MODBUS

Hi all,

I'm developing my own home automation with some arduinos, esp32 and IBM Watson.
I would like to add also my air conditioning that have a ModBus RS485 comunication to IBM Watson.

Do you have any suggestions about how the communication ModBus/MQTT to Watson can be made? There is any gateway available on market?

Thanks
André

Please define what IBM Watson is in that context. The only meaning I'm aware of the AI software of that name but that one doesn't make much sense in your sentence above.