Carrier 48TC**16 installation instructions Communication Wiring Protocols, General

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. 76 and 77 for protocol switch settings and address switches. The 3rd party connection to the RTU Open is through plug J19. See Fig. 78 for wiring.

NOTE: Power must be cycled after changing the SW1-3 switch settings.

Refer to the RTU Open Controller Integration Guide (Catalog No. 11-808-428-01) for more detailed information on protocols, 3rd party wiring, and networking.

SW3 Protocol Selection

PROTOCOL	DS8	DS7	DS6	DS5	DS4	DS3	DS2	DS1
BACnet MS/TP	Unused	OFF	OFF	OFF	ON	OFF	Select Baud	Select Baud
(Master)
Modbus	Unused	OFF	OFF	ON	ON	OFF	Select Baud	Select Baud
(Slave)
N2	Unused	OFF	OFF	OFF	ON	ON	OFF	OFF
(Slave)
LonWorks	Unused	ON	ON	OFF	ON	OFF	OFF	OFF
NOTE:
DS = Dip Switch

BACnet MS/TP SW3 example shown

Baud Rate Selections

BAUD RATE	DS2		DS1
9600	OFF		OFF
19,200	ON		OFF
38,400	OFF		ON
76,800	ON		ON	C07166
		Fig. 76 - RTU Open SW3 Dip Switch Settings

48TC**16

C10815

Fig. 77 - RTU Open Address Switches

Fig. 78 - Network Wiring

C10816

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