1.there are 4 modes in interface1.0, but most inverter/ems system only using 2 modes, which is mode 2(normal operation) and mode3(boost the temperature), and trigger by pv Surplus energy, is that mode1 and 4 are never working in a storage system?
2.there is 2 ways to connect sg signal to heatpump, DO dry contacts straight control the pump or drive a external relay to control the pump, dry contacts are able to transfer 2 sg signal but a relay only transfer 1 sg signal, is that means relay control pumps are only able to using mode2 and mode3?
3.can i get any income by building a sg ready heat pump system or what is the sg ready working mechanism? If I build a EMS system to control the pump, do I still need to take the sg ready signals from Power Supply Bureau, or I just using the EMS system to control my hearpump?
BWP SG ready:https://www.waermepumpe.de/normen-technik/sg-ready/