EasyIO FS32 – User Reference v1.4
6
RS485 Specification
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.
The FS series DOES NOT have any build-in 120 Ohm resistor. A physical 120 Ohm resistor is required and
EasyIO do not supply them.
Lightning protection circuit is highly 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 (it is not
recommended).
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.
Physical Interface 1 and
EIA-485 (BUS A,B) Two-wire, Half Duplex
2 (Port 1 and 2)
Modbus Baud Rate
Speed:(9.6K, 19.2k, 38.4K, 57.6K, 115.2K bit/s)
Data Bit:(8 bits)
Parity:(None, Even, Odd)
Bacnet Baud Rate
Speed:(9.6K, 19.2k, 38.4K,76.8K)
Data Bit:(8 bits)
Parity:(None)
Ethernet Support
IP, TCP, UDP, ICMP, HTTP,FTP
Application Support
Sedona, Modbus, Bacnet and Tcom
Daisy Chain Network Topology
RS485 Connection Diagram
