Modbus is used to control the Fronius in certain situations. If you have a grid-tied ESS system and you have selected not to feed in excess AC coupled PV or have an active feedin limit then the Fronius will be curtailed using Modbus commands regardless of its location. It’s only when the grid fails that a Fronius on AC out will be controlled by frequency shifting.
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Has the DNO settings on the fronius controlling priority been set to modbus control?
It looks a little different with the fronius newer firmware, but the principles remain the same. I have found even with the PV assistant and being offgrid this setting matters.
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I was not aware of that as we do not delve into the grid tied ESS, but handy info all the same. Thank you.
My point was that in off-grid, we use the frequency control due to its basic reliable nature.
I may have to research further if there is any advantage of using Modbus.
Cheers
Got my new cerboGX, and promptly shut the system down for an hour whilst I found the new setting to use the canbus as BMS.
The network port worked, plugged into the switch, immediately added the Fronius to inverters and got the modbus working.
Thought I’d updated the Fronius firmware, but apparently i only went halfway and had to reupdate about 20 versions. In doing so found the new settings in DMO Editor being for the soft limit. Tried to get this to control over modbus, survey says no. Tried voltage restriction in the DVCC, again survey says no.
So it seems that the only way that the Cerbo will control the Fronius is by increasing the frequency via the Multiplus.
Such a disappointment.
Can you please explain how you got to change the FILmax parameters.
I need to change them as my home appliances “ induction hob “ dose not like frequencies above 51.8Hz.
So I need to make the fronius frequency tolerances more stringent. So that I can go with more subtle frequency parameters in the PV inverter assistant.
Ok found it
To change Fronius Primo Frequently parameters FIL max & min use access code 77634