What is the main differences between Adapter G1 and G2？

The essence of the first  generation heat pump box is a dry contact. Since the input/output voltage of  the heat pump is set to about 220v, it cannot be directly connected to the  communication port of the inverter, so a heat pump box needs to be configured.The first-generation box connects four pins 3, 6, 7, and 8 (7.8 is for dry  contact). For the dip switch, it needs to be turned to off when connecting to  the hybrid machine, and it needs to be turned on when connecting to the  on-grid machine.The 2nd generation box connects four pins 3, 4, 5 and 6 (4.5 is RS485).  Communication is via RS485. The communication setting on the inverter needs  to be Adapter box G2. Later, EVC and heat pump boxes will be supported to be  connected together and used alternately.