Communication MODBUS485 - Big distances.

My name is Belén and I would like to ask you one question.

We want to build a communication between different Arduinos using MODBUS 485 Master/Slaves. The point is, that the distance between the Arduinos are 20 meters, so it is impossible to connect them using cables. There are some kind of modems in Arduino, that we could use? Which Arduino, do you recommend to make this communication.

Thank you very much,

Best regards,

Belén

I'd use an ESP8266 and connect them to a wifi network. Then use modbus TCP-IP. There should be some libraries to handle that, but ESP8266 requires 3.3V if I'm not mistaken.

The point is, that the distance between the Arduinos are 20 meters, so it is impossible to connect them using cables.

That cannot be a problem of the distance, RS-485 is defined up to 1200m. So why is it impossible to use cables? RS-485 is only defined on wires (cables). You might have to tell us what you're trying to achieve and what prerequisites you have on that.

pylon:
That cannot be a problem of the distance, RS-485 is defined up to 1200m. So why is it impossible to use cables? RS-485 is only defined on wires (cables). You might have to tell us what you're trying to achieve and what prerequisites you have on that.

I believe he's trying to not make a mess out of cables. That's the only reason I can think of.