question

I have a similar setup. What you are looking for is to keep the existing "EVU-Kit" from the openWB setup, which is the equivalent Grid-Meter (not home meter/consumption) for a victron ESS.

IMHO, and there have been discussions in the openWB forum as well, there is no alternative to installing a Grid-meter that is compatible with a victron GX setup.

In short: the old EVU-Kit has to go (with future Version 2.x of openWB Software you could puut it to re-use as a Home-consumption meter, later).

Edit: there is a possibility with an add-on in venus-OS, somewhere to be found, here in the modifications section of the forum, that would allow to use other meters than the carlo gavazzi line of meters. But again, thiss is not what you asked for.

Once this is done, the openWB setup for the EVU-Kit module can be configured to use the GX (as well as the battery storage (Speicher).

This is what I've done.

Also, I noticed that the GX does query the Grid Meter (EM24) more frequently (approx one per second), whilst openWB does this only every 10sec.

So even if what you are asking can be achieved, the resolution and quality of the grid-meter data from openWB will be reduced compred to the victron ESS standard. I actually don't know if this would have an impact on the functionality.

Edit: So I'd recommend to either go for an EM24 or use the modifications add-on for venus-os to use tge SDM as grid meter...do not use the openWB as grid metering source

P.S.: there is agerman speaking section here, in the victron forum, too.

As a general disclaimer:

Yes, this is possible, but the EM24 will be the more robust solution, as it does not include potential point of failure like Wifi, Network, the script got stuck etc.

In general you will have to turn to github to find possible solutions, like this one here: https://github.com/stormmurdoc/victron_sdm630_bridge

For openWB, the basic procedure would be:

1. Setup an environment (python script, iobroker, nodered, etc) where you can subscribe to the relevant openWB MQTT topics required for this
2. If required, compute missing values
3. publish the required values either using MQTT-DBUS bridge or write them onto the DBUS directly - the linked solution will provide you some details about it

Also be aware that most solution will not survive a firmware upgrade of Venus OS, some even have problems when restarting the Raspberry.

Here some more links:

https://github.com/victronenergy/dbus-mqtt

https://github.com/victronenergy/venus/wiki

https://github.com/RalfZim/venus.dbus-fronius-smartmeter

For installations that I take care of (friends), I always go for the EM24. Any other solution will be more fragile - be prepared to got bug-hunting in the middle of the night, when a script went berzerk.

Just happened to me last week :-/

Hi @Markus71 ,

searching the Forum (Space: Modifications) I probably found your solution - under the assumption that the SMD720D-N is "outside" the openWB and cann be adressed / polled directly:

https://community.victronenergy.com/idea/114716/power-meter-lib-for-modbus-rtu-based-meters-from-a.html

Give it a try. Won't become easier than following that thread, i guess.

Thanks guys for so many quick answers. After reading everything I have decided, that it will be the better way for me to replace the OpenWB-Kit by an EM24. I need a stabile running system and don't want to fix stuff after each update of venus OS.

Do you have a recommendation, if I should go for either the lan- or the rs485-version of the EM24? Both would be possible because I have lan access at the place, where the EM24 will be installed. The rs485 version seems more safe for me because it does not depend on the Netwerk. Does the lan-version have other advantages?

Ich habe wirklich noch Zeit, bis meine Zellen da sind. Also mal angenommen, der EM24 wäre verfügbar, dann Frage wie oben.

Wenn Du den EM24 oder den ABB (Edit: OK, beim ABB weiss ich es nicht genau...muss openWB-seitig evtl. angepasst werden) installierst (mit dem victron GX verbindest und aktivierst), kann openWB den direkt verwenden...EVU-Modul Victron GX ....Speicher Modul ebenso. Das alte EVU-Modul kann dann raus oder später als Hausverbrauch eingebaut werden (oenWB V2 kann weitere Zäher, die aktuelle 1.9x berechnet den Hausverbrauch intern.

edit: Achso, Du willst ja VenusOS aufm RPi...dann wird/ist der RPi Dein GX.

Aber das ist eher was fürs openWB forum, hmmm?