Using existing equipment with OEM?

I’m just getting into monitoring, driven in part from a solar PV install. I have the following equipment in place and working.

Solaredge 6000 and 7600 inverters
WattNode ModBus meter (RS485)

Right now, the WattNode is connected to the 7600 inverter and both inverters use Ethernet to update the Solaredge monitoring portal.

That’s OK overall, but I would really like more up to date data, particularly for consumption. If I watch the screen on the inverter, I can see it update the consumption data from the meter about once a second. The consumption meter is installed on the lines going to the indoor breaker panel, after the inverters and grid connections, so it measures just the consumption. The Solaredge inverters seem to be pretty accurate measuring generation, so that information is available as well.

What I’m considering doing is using the python interface at to pull the
inverter data in RS485 master mode using a Raspberry Pi 3 with a USB RS485 adapter. Then formatting that into a compatible packet to upload to OEM running on the same Pi machine. Then using a second RS485 adapter to grab the wattnode data as well. Or even just using the Solaredge API and living with less frequent solar data.

I know I would need to write some interface code to connect them up, and would be willing to contribute that to the project if the maintainers are interested. I just wanted to put the idea out there to see if there is already something like it available or there is a problem I’m not seeing in doing it.

Hi Travis,

Here’s some info that should help get you started.

I did something similar to pull data off my MVHR unit. I simply convert the data to an MQTT stream for EmonCMS to pick up. If you want data and an embedded time stamp, then use the HTTP API.

Thanks for the info. I managed to modify the script to work with the WattNode, the register numbers had to be updated, and it doesn’t seem to do as much as the unit used in the original script. I just have it report current energy use and OEM seems to track it pretty well.

I’d like to add Solar generation as well. As I’m in the US, my WattNode only has one channel left, so I don’t think it will work. I think I can come up with a way to get info from the inverters, but I was curious to see what other options might be available. Solar nameplate rating is 15.6kW, the tie-in breaker is a 75A dual.

I was just going to keep using the solaredge portal, but they keep breaking my meter setup. So far, this project is more reliable.

Another option might be to use the RTL-AMR project to feed data in. I have managed to receive my smart meter consumption data with it. I need to look for the generation and/or net data though.