Hi all, The Venus OS supports the integration of PV inverters via TCP Modbus if the PV inverters support Sunspec. I have two suggestions for this that offer additional benefits and, according to my research, shouldn’t require too much development effort. Feature Request 1 Support for Sunspec PV …

Kan het zijn dat de Sunspec regeling geen rekening houdt met max grid-feedin? Edit: Sorry for the Dutch, I added English below: Can it be that the Sunspec management ignores max grid feedin?

I had an (experimental) setup with a Sunspec-compliant inverter on AC-out. It was correctly discovered by GX. PV management and communication was verified by me by using Node-Red (PV inverter / Power Limit) as well as playing around with the Grid setpoint. But I noticed that the PV is not adjusted…

@mpvader Basically I do agree. On the other hand, most TCP Modbus sticks, or even those via LAN, do nothing more than convert RTU to TCP Modbus. I’ve seen some implementations where the STCP Modbus interfaces represented a bottleneck. It’s certainly not Victron’s job to solve the manufacturers’ …

Has anyone experience with connecting a Sungrow Inverter? It’s a SG10RT with WiNet-S LAN Dongle.

Where, in Node Red, did you find the “limit calculated by venus OS”? I couldn’t find it myself.

Hi, it is part of the Victron PV Inverter Node. [image] [image]

Hmm, not here: [afbeelding] Nevermind, don’t want to hijack your topic

mhhh MQTT does not sound like sunspec modbus tcp connected inverter. Anyhow…if limiting is supported it needs to be enabled for the inverter in question. And also a Limit needs to be configured in ESS to make the limit calculation work. [image] [image]

Ah, it must be modbus connected. But then VenusOS already manages the power limit, doesn’t it? Why setting the limit youself, too?

Support of Sunspec Inverters via Modbus RTU and extended Sunspec Support

Beta testing Venus OS beta testing

TheRealStefan 4 December 2025 18:52 26

That shoud be available starting 3.70 ~50

See release notes:

Topic		Replies	Views
Growatt MQTT to SunSpec Modbus TCP Bridge for Multiple Inverters Node-RED diy , ess	6	271	4 August 2026
Anbindung von PV Invertern an Cerbo per Modbus RTU & TCP Deutschsprachiger Bereich pv_inverter , cerbo_gx	0	469	20 November 2024
Solaredge communication dropping every few minutes Q&A and troubleshooting vrm , multiplus-ii , cerbo_gx , solar_edge	287	8183	18 August 2026
AC PV Inverter power limiting via virtual device, possible? Node-RED ess , pv_inverter , cerbo_gx	17	567	25 August 2026
Koppelen Huawei SUN2000 inverter aan Victron VRM DIY diy , ess , vrm , multiplus-ii , cerbo_gx	2	165	21 May 2026

Support of Sunspec Inverters via Modbus RTU and extended Sunspec Support

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