How to input multiple solar power Watt values

[gert3d]

My solar power inverter does not have internet capabilities, so I use S0 ports of kWh meters to measure the production data from two inverters, using an Arduino Pro Mini, and some input circuitry. That works fine, however I had problems finding a way to show the data in one grah in Domoticz, by directly sending device parameters via JSON.
I decided to use the Ampere 3 Phase device, that does the trick, but with wrong legends of course.
Is there another way getting whatever multiple data, combined in a database/graph ? A more universal set up?