Two Fronius Inverters, and a smart meter


I’ve gone through the help files and forums, but haven’t had any luck.

My setup is:

Two Fronius Inverters 5kw, both have their own datalogger ID
One Fronius Smart Meter.

I set one inverter to send data using

Solar API v1 - Current Data - inverter

code: /service/r2/froniuspost.jsp?sid=MYID&key=MYKEY&dayenergy=1&delay=5&auto=1&v6=Voltage_AC_Phase_1&nodayenergy=1

Solar API v1 Current Data - meter


Solar API v1 - Logdata - Data


Now, with the above, i an establish a successful connection.

However, the data showing as generated, is not not accurate as solarweb shows greater.

What am i doing wrong ?

Any help / advice appreciated.

The hourly log push should display the exact data as the Fronius every hour.

The nodayenergy=1 is not longer used. Use dayenergy and it is only applicable on the inverter push.

Day energy should be enabled (dayenergy=1) unless the inverter is using a firmware that had issues with generation not increasing.

Ill make those adjustments shortly.

Confirming I only need to configure the push settings on 1 inverter and not both ?

Have setup Data Aggregation.


Sorry, missed the part that there were two data loggers. Yes the Data Aggregation feature will help with this. Push both inverters to two child systems and create a parent to represent the total of the two.

The meter data can be either pushed to one of the children or the parent directly.

This week I put another Fronius inverter Primo 3.0.1 in my system.

I put the secondary inverter in slave mode, that consequently disable the datamanager.

So I connect both inverters through the solar net cable, using the “out” conector in the First (master) and the “in” in the second (slave) inverter.

It worked fine and I didn’t have to make any adjusts in the Pvoutput. It sum all data automatically on Pvoutput, like you have just one inverter.

Pay atention in the terminators on the solar net conectors on both inverters. If you let one of it out, the inverters will not work.


Exactly this (edupenna). The Fronius will do it all for you

Hi. I just added a second Fronius Primo inverter which is set up as a slave to the original.
Solarweb is aggregating fine but PVOUtput is still only seeing the first inverter’s data.
Are there any changes I need to make in the push service?

Edit: I added an hourly log catch-up and that seems to correct it, but I’d prefer 5 min updates if possible.

Aggregation requires all child systems to be assigned to a parent. To combine 2 systems to a parent, a minimum of 3 systems is required.

Assigning one child to a parent will simply copy the child data to the parent.

Thanks for responding @bankstownbloke.
I haven’t ‘aggregated’ in PVOutput - the two inverters are connected with a cable and aggregates in the Fronius data manager.

It’s working well, but only by adding hourly log data.

IME/IMO the only energy/power data to rely on from Fronius data push to PVO is that from the hourly log data push.

The way PVO works with the 5-min data push is prone to inaccuracies due to sampling error - that’s because in the Fronius data push there are different values provided, including:

  • a momentary sample of power production (or consumption) taken at the instant of the data push, and
  • energy accumulation values at the time of the data push.

PVO uses the momentary sample of power output rather than the energy accumulation value (from which you can calculate an accurate 5-min average power value).

If at the moment of the Fronius data push a cloud was passing over and power output was low but for the rest of the 5-min it was cloudless, the power value PVO uses is the momentary sample while the cloud was overhead, rather than use the total energy accumulated during the past 5-min to calculate the 5-min power average.

When a log push occurs (which contains all the energy accumulation values at 5-min intervals for the day up to the time of the log push), PVO then uses the energy accumulation values to correctly calculate the 5-min power averages and correct the sampling errors created by the way it uses the data from the more frequent 5-min data push.

I’m still not sure why PVO uses the power sample data rather than the energy accumulation values from the Fronius data push. These instantaneous samples are not particular useful for this sort of power monitoring. This instant sample data is more suited for systems which monitor/display/record power on a real time, second by second basis.

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