Modbus RTU to TCP

Configuration
1

Not that many modbus topics over here.
I have a ventilation system which supports a modbus (RTU). Seems HA is supporting this protocol.
What i would like to do is connect the ventilation system which will somehow conver it to a TCP and than connect it via wifi to the HA.
So the question is how to convert it to TCP. Wonder if thic can be done via raspberry and modbus usb adapter?

2

Maybe one of these?

http://www.bb-elec.com/Products/Ethernet-Serial-Servers-Gateways/Ethernet-Serial-Device-Servers/Vlinx-VESP211-Series-Ethernet-to-Serial-Converters.aspx

3

Well last i’ve seen the cost for such solutions was above 100EUR. I can see on option could be to install openhab with a modbus binding and than connect HA via rest - but that’s more like a last resort solution.
Also have found this project which looks promissing as MQTT will provide a more homogeneous enviroment

4

I found this tool and it works great!

5

btw: I have done some more development on Wagner’s code: https://github.com/mbs38/spicierModbus2mqtt
In case someone needs it :slight_smile:

1 Like
6

Any description of hardware used would be awesome!

7

You mean the USB to RS485 adaptor or the endpoint device?

8

So, yes, you’re using a USB to RS485. Connected to what kind of WiFi device? ESP? Raspberry? Arduino?

9

There is no WiFi involved.

My setup is basically:

[some PC with Linux+spicierModbus2mqtt+Home Assistant]
|
|
USB cable
|
|
[USB to RS485 converter]
|
|
RS485 cable
|__________________________________[Modbus RTU capable I/O module #2]
|
[Modbus RTU capable I/O module #1]