The BPC2 is a very simple device with 2 groups of 4 relays, with one common to each bank of 4 relays - just like the BPC1. But that is where the similarity ends.
The relays are triggered by AUX1(ON) or AUX2(OFF), per each TMCC TR or ACC ID; of which there are 8 IDs per BPC2.
You can set the relays to power back up in the state they were in before power down of your layout. Thus you can restore power to selected blocks automatically at layout power up time.
The status of the BPC2 will update the iPad screen when operated from a Cab.