Fronius inverter e.g. Symo, setting "Maximum feed-in power" and dynamic power eduction algo via ModbusTCP

[Jusufs]

Hi,
I need to enable/disable the internal "dynamic power reduction" algorithm using the ModbusTCP protocol. I found only the modbus address for the register of fixed percentage power limitation (0-100%).
Do you know if it is possible to activate/deactivate this algo only from inverter service web page, or if there is a holding register for activating/deactivating dynamic power control of the inverter, please?
In the activated mode, the inverter itself monitors the so-called "Maximum feed-in power," ensuring minimal overage power injection into the distribution network. Thank you for your responses.

 

[kommando]

More RS485 info here

https://www.fronius.com/~/downloads/Solar%20Energy/Operating%20Instructions/42,0410,2049.pdf

 

[wattmatters]

Hi,
I need to enable/disable the internal "dynamic power reduction" algorithm using the ModbusTCP protocol. I found only the modbus address for the register of fixed percentage power limitation (0-100%).
Do you know if it is possible to activate/deactivate this algo only from inverter service web page, or if there is a holding register for activating/deactivating dynamic power control of the inverter, please?

See if this Home Assistant thread gives any clues:

Automate Fronius Soft Limit

Hi Juande, Your setup is more similar to my requirements but the offer of a blog from Brett is a good idea too. As I’m wanting to setup the same sort of thing with limiting export (due to unpredictable negative FIT pricing on the wholesale market). Can you post your additions to the .yaml file &...

community.home-assistant.io

 

[Jusufs]

See if this Home Assistant thread gives any clues:

Automate Fronius Soft Limit

Hi Juande, Your setup is more similar to my requirements but the offer of a blog from Brett is a good idea too. As I’m wanting to setup the same sort of thing with limiting export (due to unpredictable negative FIT pricing on the wholesale market). Can you post your additions to the .yaml file &...

community.home-assistant.io

Thank's I found this article. Hard limitation for some time period works. But I need to activate Fronius internal algorithmus for dynamic power production. I will use it to reduce production if spot price isn't good :0)
I wrote some ESP32 S3 code, for Solaredge inverters - they are able to activate/deactivate internal algo via modbus.

 

[Sergio95050]

I wrote some ESP32 S3 code, for Solaredge inverters - they are able to activate/deactivate internal algo via modbus

I'm all ears - not seen any SE doc describing registers for writing e.g. changing settings. Would you share, please ?

 

[Jusufs]

I'm all ears - not seen any SE doc describing registers for writing e.g. changing settings. Would you share, please ?

 

[Sergio95050]

Thanks, but no cigar. (URLs would be sufficient next time )

I'm working with the well-known docs from version 1.0 (last one is 2.7 , BTW).
There is nothing revealed about MODBUS registers with SE _Settings_ nor writing something to some regs.
SE keep us on short leash - you must use LCD+one button or SetApp if you want to change something....

 

[Jusufs]

In second pdf you have all modbus implementation description. If you know modbuspoll program, you can try to read/change some hplding registers.

 

[Sergio95050]

you can try to read/change some hplding registers.

I did - no dice, SE specifically stated in the docs - registers for READING !

 

[Sergio95050]

In second pdf

Well, the two PDFs are the same document in two old versions. Take latest one - v2.7

 

[Sergio95050]

I wrote some ESP32 S3 code, for Solaredge inverters - they are able to activate/deactivate internal algo via modbus.

Sorry, but it was false claim, you did not make it.

 

[Jusufs]

Yes sorry, in this documents are readonly registers.

 

[kommando]

The registers must exist as the Solar-log component listing shows the Fronius Symo as being supported and both active plus reactive power reduction being achievable. I use the Solar-log with my SMA Sunny Boys, there is a field for entry of the SMA Grid code to allow the Solar-log access to control power output and I can confirm it works for SMA SB's.

Solar-Log™ supported components

Component database - Here you can find the components supported by Solar-Log⢠â 130 manufacturers â 2,300 components

www.solar-log.com

So you will probably need the registers for power control and the register to unlock control of these registers.

If these are not documented then you will have to query the Inverters registers outside of the documented ranges using something like

https://github.com/SciFiDryer/ModbusMechanic

 

[Sergio95050]

So you will probably need the registers for power control and the register to unlock control of these registers.

Well, without documented bits/bytes/format and sequencies, no one of wonderful MODBUS programs [Java or not] WILL NOT reveal you the "unlock" and required values to control your device. Sorry.
Perhaps, reverse engineering of original management program from the manufacturer will help you. Partially, as I found...

 

[Sergio95050]

Yes sorry, in this documents are readonly registers.

Accepting that... In your shoes, I would remove your statement above "I wrote some ESP32 S3 code, for Solaredge inverters - they are able to activate/deactivate internal algo via modbus" to avoid confusing other members here.

 

[Jusufs]

I agree,if the comparison of modbus for Solaredge versus Fronius is confusing, let's delete the info. No problem from my point of view.