Carrier 50HCQ04---12 - Manual (Page 10)

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C10821
Fig. 10 -- Enthalpy Switch and Sensor Wiring
Communication Wiring--Protocols
General
Protocols are the communication languages spoken by
control devices. The main purpose of a protocol is to
communicate information in the most efficient method
possible. Different protocols exist to provide different
kinds of information for different applications. In the BAS
application, many different protocols are used, depending
on manufacturer. Protocols do not change the function of
a controller; just make the front end user different.
The RTU--OPEN can be set to communicate on four
different protocols: BACnet, Modbus, N2, and LonWorks.
Switch 3 (SW3) on the board is used to set protocol and
baud rate. Switches 1 and 2 (SW1 and SW2) are used to
set the board’s network address. See Fig. 11 and 12 for
protocol switch settings and address switches. The 3rd
party connection to the RTU--OPEN is through plug J19.
See Fig. 13 for wiring. Refer to the RTU--OPEN 3rd Party
Integration Guide for more detailed information on
protocols, 3rd party wiring, and networking.
NOTE: Power must be cycled after changing the SW1--3
switch settings.
I--Vu OPEN
I-Vu OPEN is a Carrier front-end and Building
Automation System (BAS). It is a web based network
system that uses a native BACnet over MS/TP
communication protocol. The speed of the network can
range from 9600 to 76,800 baud. OPEN devices
communicate with a proprietary language called Linkage
on I-Vu OPEN. Linkage is established automatically and
allows the flow of specific data across OPEN devices.
Refer to I-Vu OPEN literature for more information on
I-Vu.
BACnet MS/TP
BACnet Master Slave/Token Passing (MS/TP) is used for
communicating BACnet over a sub--network of
BACnet--only controllers. This is the default Carrier
communications protocol. Each RTU--OPEN module acts
as an MS/TP Master. The speed of an MS/TP network can
range from 9600 to 76.8K baud. Physical Addresses can
be set from 01 to 99.