Please notice that, if you use the Multiplus II relay directly like it is in the documentation it will probably burn one of the other, the Multiplus II or the SolarEdge.
As I said in the other thread, Multiplus has a 12VDC power supply on its open collector and the SolarEdge board is a 5.VDC board. I got not clue about what could happens to them in case you close a 12VDC voltage to a board that should receive 5VDC.
If you want to use the Multiplus II relay you should consider using a physical relay or a optocoupler for galvanic isolation. Also, you may use the Cerbo relay if you have Cerbo GX on your system.
In my system I did the following:
Notice the logic!
I wish I had already tested my system so I could you give you “real” feedback. So, do not take this configuration as workable!
Lets wait to see if some “expert” come into this hread and bring some light to both of us.