Communications Wiring; Protocol Overview - United Technologies Carrier Unit Vent Open Integration Manual

Communications wiring

Protocol Overview

You can set the Unit Vent to communicate 1 of 4 different protocols:

BACnet MS/TP (page 4)

BACnet ARC156 (page 8)

N2 (page 9)

Modbus (page 11)

LonWorks (page 13)
The default setting is BACnet MS/TP. You set the protocol and baud rate on the Comm Selector DIP switches on
the controller. See table below for specific switch settings.
The third party connects to the controller through the Comm port for BACnet MS/TP, N2, Modbus, and through the
Option Card port for the LonWorks Option Card.
NOTES

Changing protocol requires no programming or point assignment by the installer or operator.

Power must be cycled after changing the Comm Selector DIP switches or connecting the LonWorks Option
Card.
Comm Selector DIP switch settings for protocols and baud
Protocol
BACnet MS/TP
(Default)
BACnet ARC156
1
N2
Modbus
LonWorks 2
1
N2
must have 9600 bps baud
2 LonWorks
must have 38.4 kbps baud
Baud Rate
9,600 bps
19.2 kbps
38.4 kbps
76.8 kbps
(Default)
Unit Ventilator
Integration Guide
Baud Rate
3 4 1
Off Off Select Baud
Off Off N/A
On Off Off
Off On Select Baud
On On On
1 2
Off Off
Off On
On Off
On On
2
Select Baud
N/A
Off
Select Baud
Off
3
Communications wiring
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