Hi Coulomb,
i use an inverter 5kVA-48 plus duo and bought this one from:
https://voltaconsolar.com/conversol-5kva-duo-mppt-inverter-charger.html?___SID=U
They provide an update on their website, but these files are password protected. For some reason, they are not willing to tell me the password. Very bad after sales support :-(
https://voltaconsolar.com/monitoring-software
So i'm interersted in your firmware. My inverter is running on 75.20
Thanks,
Rik