Appendix F : Application of RS-485 Network
The RS-485 length can be up to 4000 ft or 1.2 km over a single set of twisted –pair cables,
if the RS-485 network is over 4000 ft or 1.2Km, the RS-485 repeater must be added to
extend the RS-485 network.
F.1: Basic RS-485 network
The basic component of the RS-485 network consist of a Master Controller (or using a PC
as Host controller), and some RS-485 devices.
F.2: Daisy chain RS-485 network
All RS-485 devices are wired directly to the main wire, If the network is up to 1.2 Km, it will
need a repeater (I-7510) to extend the network.
F.3: Star type RS-485 network
There are branches along the main wire. In this case, it is better to have a repeater to
isolate or filter the noise that is made by devices
RU-87P1/2/4/8 User Manual, Version: 1.2
62