As @sulzbacher mentioned above I have written a PHP script to extract CONSUMPTION and PRODUCTION data from a Fronius GEN24 inverter using the existing API. The extracted data are then pushed to PVO. His GEN24 also has a Fronius Data Meter to measure IMPORTED and EXPORTED energy.
The GEN24’s API calls are rather unhelpfully not the same as my Symo. One thing that is noticeable different is that the GEN24 only appears capable of returning LIFETIME CONSUMPTION data from the attached Fronius Smart Meter as opposed to daily consumption data. I noticed too that the GEN24 returns unreliable data if it is queried at precise 5 minutely intervals [ e.g. 00:05, 00:10, 00:15 … ]. I added a short delay [ 15 seconds ] at the start of the script to allow the GEN24 to update itself - I am guessing that it performs internal housekeeping every 5 minutes. Less than 15 seconds proved to be unreliable - the GEN24 and my host computers were both synchronised time-wise.
suzbacher has also pointed out to me that there is a new API call that has appeared which could potentially provide the same data with a single API call rather than the three that I am currently making. On that basis I wasn’t planning on publicly posting my PHP script anywhere in the interim.
The new but undocumented API call returns quite different information from suzbacher’s GEN24 and my Symo.
If anyone is looking for a script that uses the existing API and has a GEN24 I am happy to P.M. them a copy.
Many thanks to suzbacher for allowing me to do all of my testing against his GEN24.
For anyone that is interested the new API call is http://fronius/components/readable