Inbio260 can at most support four FR1200, two as in, two as out. There are six DIP terminals , 1-4 is for RS485 address , 5 is reserved , 6 is for extending the length of RS485. Set the odd number is for enter reader, and the even number is for exit reader(for example , two readers for one door- the rs485 address 1 is for enter door, rs485 address 2 is for out door ) And both 1 and 2 should be translate into the binary digits.