Eastron SDM630 3-phase modbus / rs485 kwh meter - how best to connect?

Hi, i have purchased an Eastron SDM630 Modbus RS485 3-phase kwh meter (mid certified) to measure what goes into my electic car. It will be installed right after the 3-phase circuitbraker (eart breaker).

So i need some interface now from the rs485/modbus on the sdm630 to my openhab installation.

When googling around I come across either rs485-USB OR rs485-Ethernet kind of devices. But it remains somewhat unclear to me what is best to use (supported).

What would be the most convenient way to connect this rs485/modbus meter to my OpenHab implementation ? And maybe specifc device suggestions ?

PS - i might add a few more of these modbus meters to measure my heatpunt and solar panel output.

Thanks for any reactions

reg Koen

You can use it:

Hi thanks, forget to mention - i am using the Odroid N2+ (due to pi unavailability)

So has to be ethernet or usb or some odroid board ?

thx koen

Modbus tcp

yeah thx - also find these kind of devices - usb / lan / wifi connected etc several brands

I would like to know what is supported by openhab and and what works best (someone working with a specific device)

I also use the Elfin for about 1 year now without issues

openHAB supports both common varieties of Modbus.
Modbus-TCP talks over ethernet or WiFi.
Modbus-RTU talks over some kind of serial hardware. That’s usually RS-485, but doesn’t have to be.

Obviously, wherever openHAB is hosted you would need a hardware port to allow communications of the type that you have chosen
Most server hosts will have ethernet already.
Some will have serial of some kind.
But for wired RS-485 you almost always need a USB-485 dongle.

Your meter has only wired RS-485.

You’d normally add a USB-485 dongle to your server and a length of cable.

Modbus gateways are available that can interface Modbus-TCP over WiFi or ethernet to Modbus-RTU over wired RS-485.
These are transparent in operation - openHAB would neither know nor care if you used one of those, so there simply is no “support” as such.

Just like a USB-485 dongle, the gateway will drive a serial bus allowing several serial slaves to be connected.

I use the USR brand gateways, but I wouldn’t bother for this purpose, would use a cheap USB dongle.

hi ross , many thanks ! will take that into account !
hi darkog also thanks !

guess i am thinking to complex about it …

reg koen

hi, would this one work ?