difference between RS485 and Modbus extension

[Tom Vervecken]

What is the difference between the RS485 and modbus extension?

I thought that RS485 was a hardware layer and modbus a software layer?

if I want to use e.g : https://www.vekto.nl/docs/kwh/mutlifunctionele-kwh-meter.pdf

In the Datasheet i can read : Bus type RS485 and protocol Modbus RTU

So what extension should i use?

[smartbusinesstools.be]

That's correct. The modbus extension and software in Loxone Config implement the modbus protocol, so it's easier to use.

Using an RS485 extension would likely require you to program the modbus software layer yourself in PicoC.