How to wire a C-Bus Automation Controller to SE8350 or SE8650 Room Controller for Modbus RS-485 communications


09 September 2022

C-Bus Automation Controller Power Supply - Requirements
24V DC (+/- 5%), 10W max, 2W typical

SE8350/SE8650 Power Supply - Requirements
24V AC (+/- 15%), 50/60Hz, 6VA (0.25A)

Modbus RS-486 Cabling - Requirements
D1+ and D0- = Twisted Pair, Shielded, Imp 120Ω - eg Belden 9842
COM = Common (Reference) Wire

The 5500NAC2 and 5500AC2 contain the following optional in-built terminators options:
low power terminator of 120 Ω + 1 nF via link AT–BT
legacy terminator of 120 Ω via link BT-A

5500NAC2 or 5500AC2 - D1+ connector is wired to pin 13 (RS-485 +) on the SE8350/8650               - shown by brown wire
5500NAC2 or 5500AC2 - D0- connector is wired to pin 14 (RS-485 -) on the SE8350/8650                 - shown by blue wire
5500NAC2 or 5500AC2 - COMM - connector is wired to pin 15 (RS-485 REF) on the SE8350/8650     - shown by green wire

Modbus RS-485 communication line must be terminated at each end
C-Bus Automation Controller  to SE Room Controller Modbus Wiring

Refer to the 5500NAC2 or 5500AC2 Quick Start Guide and User Manual for further details regarding the C-Bus Automation Controller Power Supply and Modbus RS485 Modbus wiring connectors and wiring/electrical requirements. These can be found by scrolling to the bottom of the product page and downloading the applicable pdf

Refer to the SE8350 or SE8650 Installation Guide for further details on the wiring connectors