User's Manual

Elpas Local Controller 3 – Installation Guide
www.elpas.com
Page 3 of 6
V7/Jan 2015
RS-485 BUS/Stub Topology
The RS-485 BUS MUST BE wired using a BUS/Stub topology where the BUS Master (an ELC) is connected at any location
along the BUS. The topology supports data transmission between the ELC and up to 15 BUS Devices (such as RF/IR Readers;
LF Beacons, Display Panels and I/O Boxes) using multiple Elpas RS-485 Junction Boxes (P/N: 5-JBA00485).
IMPORTANT NOTE: Only 1 ELC and up to 7 RF BUS Readers may coexist together on a single RS-485 BUS.
200M/650Ft: Max. BUS length 10M/30Ft: Max. Stub length 100 Ohm Termination: Required each end of the BUS.
Recommended Cable/Power Supply Types:
BUS Backbone:
CAT5 solid (4x2x26AWG).
Power: Three twisted pairs
(six conductors) between Junction Boxes.
Data: One twisted pair (two conductors) between Junction Boxes.
Power: 16 to 28 VDC/2.5A Limited.