The RS-485 bus should be made up of a twisted-pair cable with characteristic impedance between 90 Ohm and 120 Ohm. Maximum bus length is about 1000 m. Depending on the EAC system, a maximum of 32 units (31 communication hubs plus the EAC, when using the DIP Switch for RS-485-addressing) can be connected to the same bus.
Connect all RS485 A connectors together and all RS485 B connectors together, depending on connection type, see figures Figure 1 and Figure 2.