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

BACview6 Handheld

The BACview6 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 BACview6 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 BACview6 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.

48TC

C07170

Fig. 68 - BACview6 Handheld Connections

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Carrier 48TCA04---A12 appendix RTU-MP Troubleshooting
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