Installation Guide

10
Installation
RS-485 Connection
You can connect the Input Module to a master device.
•
Use an AWG24 twisted pair with less than 1.2 km in length for the RS-485 cable.
•
If connecting with a RS-485 daisy chain, connect the termination resistor (120 Ω) to both ends of the daisy
chain connection. If connected to the middle line, the signal level becomes smaller and the communication
performance will deteriorate. Make sure to connect it to both ends of the daisy chain connection. Set the
termination switch(TERM) to ON for Input Module.
•
RS485 wire size shall be over 26 AWG and all wiring must comply with National Electrical Code, ANSI/NFPA 70.
Master Device
Slave Device
Terminating
resistance switch
Slave Device
RS-485
TRX+
RS-485
TRX-
Terminating
resistance
(120Ω)
GND