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Carrier 48TCA04---A12 User Manual

Page 49

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49

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--MP 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.
Modbus
The RTU--MP module can speak the Modicon Modbus

RTU Protocol as described in the Modicon Modbus

Protocol Reference Guide, PI--MBUS--300 Rev. J. The

speed of a Modbus network can range from 9600 to 76.8K

baud. Physical Addresses can be set from 01 to 99.
Johnson N2
N2 is not a standard protocol, but one that was created by

Johnson Controls, Inc. that has been made open and

available to the public. The speed of N2 network is

limited to only 9600 baud. Physical Addresses can be set

from 01 to 99.
LonWorks
LonWorks is an open protocol that requires the use of

Echelon’s Neuron microprocessor to encode and decode

the LonWorks packets. In order to reduce the cost of

adding that hardware on every module, a separate

LonWorks Option Card (LON--OC) was designed to

connect to the RTU--MP.
This accessory card is needed for LonWorks and has to be

ordered and connected using the ribbon cable to plug J15.

The RTU--MP’s baud rate must be set to 38.4k to

communicate with the LON--OC. The address switches

(SW1 & SW2) are not used with LonWorks.

Local Access

BACview

6

Handheld

The BACview

6

is a keypad/display interface used to

connect to the RTU--MP to access the control information,

read sensor values, and test the RTU, see Fig. 68. This is

an accessory interface that does not come with the MP

controller and can only be used at the unit. Connect the

BACview

6

to the RTU--MP’s J12 local access port. There

are 2 password protected levels in the display (User and

Admin). The user password is defaulted to 0000 but can

be changed. The Admin password is 1111 and cannot be

changed. There is a 10 minute auto logout if a screen is

left idle. See Form 48--50H--T--2T, Appendix A for

navigation and screen content.

Virtual BACview

Virtual BACview is a freeware computer program that

functions as the BACview

6

Handheld. The USB Link

interface (USB--L) is required to connect a computer to

the RTU--MP board. The link cable connects a USB port

to the J12 local access port. This program functions and

operates identical to the handheld.

RTU--MP Troubleshooting

Communication LEDs
The LEDs indicate if the controller is speaking to the

devices on the network. The LEDs should reflect

communication traffic based on the baud rate set. The

higher the baud rate the more solid the LEDs will appear.

C07170

Fig. 68 -- BACview

6

Handheld Connections

48TC