EasyIO FC20 User Reference v1.3
RS485 Connection
RS485 connection must be terminated at both ends with termination resistor, typically 120Ohms. It is
recommended to use shielded twisted pair wire (STP) for the wiring. Lightning protection circuit is
recommended to be installed at one end of the wiring. The controller should be wired in daisy chain
network topology as shown as image below. If wire branch can be avoided, keep it as short as possible,
and never connect more than one device to the wire branch.
Be careful if single power supply is used for all connected RS485 device, make sure all devices are
having the same ground connection. Make sure you are connecting the same wire for the same
terminal position, all “H” terminals connected to the same wire.
Daisy Chain Network Topology
RS485 Connection
